JP4599015B2 - Extrusion coating method - Google Patents

Description

【００４７】
前記短鎖エステル単位が次式によって表され、
【００４８】
【化４】

【００４９】
式中、
Ｇは、平均分子量が約４００〜３５００のポリ（アルキレンオキシド）グリコールから末端水酸基を除去した後に残る２価の基であり、ポリ（アルキレンオキシド）グリコールによって前記１つまたは複数のコポリエーテルエステルに組み込まれたエチレンオキシド基の量は、コポリエーテルエステルの総重量を基準にして、約２０から約６８重量％、好ましくは約２５から約６８重量％であり、
Ｒは、分子量が約３００未満のジカルボン酸からカルボキシル基を除去した後に残る２価の基であり、
Ｄは、分子量が約２５０未満のジオールから水酸基を除去した後に残る２価の基であり、
前記コポリエーテルエステルは、約２５から約８０重量％の短鎖エステル単位を含有する。
【００５０】
前記コポリエーテルエステルは、ＡＳＴＭＥ９６−６６（ＢＷ法）によるＭＶＴＲが、少なくとも約２５００、好ましくは少なくとも約３５００、より好ましくは約３５００から約２００００ｇｍ．ｍｉｌ／ｍ²／２４時間であることが好ましい。
【００５１】
本明細書で用いる用語「コポリエーテルエステルに組み込まれたエチレンオキシド基」は、長鎖エステル単位の（ＣＨ₂−ＣＨ₂−Ｏ−）基の、総コポリエーテルエステル中の重量％を意味する。ポリマー中の量を決めるためにカウントされるコポリエーテルエステルのエチレンオキシド基は、ポリ（アルキレンオキシド）グリコール由来のものであり、低分子量ジオールによってコポリエーテルエステル中に導入されたエチレンオキシド基ではない。
【００５２】
本明細書で用いる、ポリマー鎖中の単位に適用する用語「長鎖エステル単位」は、長鎖のグリコールとジカルボン酸との反応生成物を意味する。適当な長鎖グリコールは、末端に（またはなるべく末端近くに）水酸基を有し、分子量が約４００から約３５００、特に約６００から約１５００のポリ（アルキレンオキシド）グリコールである。
【００５３】
コポリエーテルエステルの製造に用いられるポリ（アルキレンオキシド）グリコールは、コポリエーテルエステルの総重量を基準にして約２０から約６８重量％、好ましくは約２５から約６８重量％、より好ましくは約３０から約５５重量％のエチレンオキシド基を有するコポリエーテルエステルが得られる量のエチレンオキシド基を含有するものである。エチレンオキシド基は、水蒸気が容易に透過する性質をポリマーに与え、一般に、コポリエーテルエステル中のエチレンオキシドの比率が高いと水透過性が高くなる。第２のポリ（アルキレンオキシド）グリコールを少量含有するエチレンオキシドのランダムまたはブロックコポリマーを用いることができる。一般に、第２のモノマーを存在させる場合は、この第２のモノマーは、ポリ（アルキレンオキシド）グリコールの約３０モル％未満、通常約２０モル％未満を構成するものとする。代表的な長鎖グリコールには、ポリ（エチレンオキシド）グリコール、エチレンオキシドキャップドポリプロピレンオキシドグリコール、得られるコポリエーテルエステルが少なくとも約２５重量％のエチレンオキシド基の量を有するという条件で、ポリ（エチレンオキシド）グリコールとエチレンオキシドキャップドポリ（プロピレンオキシド）グリコールおよび／またはポリ（テトラメチレンオキシド）グリコールなどの他のグリコールとの混合物が含まれる。優れた水蒸気透過性と限定的な水膨潤性とを併せ持つので、分子量が約６００から１５００のポリ（エチレンオキシド）グリコールから調製されるコポリエーテルエステルが好ましく、フィルムに形成した場合広い温度範囲で有用な性質を示す。
【００５４】
コポリエーテルエステルのポリマー鎖の単位に適用される用語「短鎖エステル単位」は、分子量が約５５０未満の低分子量化合物またはポリマー鎖単位のことである。これらは、低分子量ジオールまたはジオールの混合物（ＭＷが約２５０未満）をジカルボン酸と反応させて上記の式（ＩＩ）で表されるエステル単位を形成することによって製造する。
【００５５】
反応してコポリエーテルエステルの調製に用いるのに適当な短鎖エステル単位を形成する低分子量ジオールには、非環式、脂環式、および芳香族ジヒドロキシ化合物が含まれる。好ましい化合物は、エチレングリコール、プロピレングリコール、イソブチレングリコール、テトラメチレングリコール、１，４−ペンタメチレングリコール、２，２−ジメチルトリメチレングリコール、ヘキサメチレングリコールおよびデカメチレングリコール、ジヒドロキシシクロヘキサン、シクロヘキサンジメタノール、レゾルシノール、ヒドロキノン、１，５−ジヒドロキシナフタレンなどの、炭素原子２〜１５個のジオールである。特に好ましいジオールは、炭素原子２〜８個を含む脂肪族ジオールであり、最も好ましいのは１，４−ブタンジオールである。使用できるビスフェノールには、ビス（ｐ−ヒドロキシ）ジフェニル、ビス（ｐ−ヒドロキシフェニル）メタン、およびビス（ｐ−ヒドロキシフェニル）プロパンが含まれる。エステルを形成する等価のジオール誘導体もまた有用である（例えば、エチレンオキシドまたはエチレンカーボネートをエチレングリコールの代替として用いることができる）。本明細書で用いる用語「低分子量ジオール」は、こうした等価のエステル形成誘導体を含めるものと解釈するべきである。ただし、分子量要件は、誘導体ではなくジオールに付随するものである。
【００５６】
前記の長鎖グリコールおよび低分子量ジオールと反応してコポリエーテルエステルを生成するジカルボン酸は、低分子量、すなわち分子量が約３００未満の脂肪族、脂環式、または芳香族ジカルボン酸である。本明細書で用いる用語「ジカルボン酸」は、グリコールおよびジオールと反応してコポリエーテルエステルポリマーを形成する際に、実質上ジカルボン酸のように機能する２官能性カルボキシル基を有するジカルボン酸の酸等価物を含む。これらの等価物には、エステル、および酸ハロゲン化物および酸無水物などのエステル形成誘導体が含まれる。分子量の要件は酸に付随し、その等価エステルまたはエステル形成誘導体には付随しない。したがって、分子量が３００を超えるジカルボン酸のエステル、または分子量が３００を超えるジカルボン酸の酸等価物は、その酸の分子量が約３００未満であれば含まれる。ジカルボン酸は、コポリエーテルエステルポリマーの形成およびこのポリマーの本発明の組成物中での使用を実質上妨げない任意の置換基または組み合わせを含むことができる。
【００５７】
本明細書で用いる用語「脂肪族ジカルボン酸」は、各々が飽和炭素原子に結合した２個のカルボキシル基を有するカルボン酸を意味する。カルボキシル基が結合する炭素原子が飽和で環状の場合は、この酸は脂環式である。共役不飽和結合を有する脂肪族の酸または脂環式の酸は、ホモ重合するので使用できないことが多い。しかし、マレイン酸などのある種の不飽和酸は使用することができる。
【００５８】
本明細書で用いる用語の芳香族ジカルボン酸は、２個のカルボキシル基が炭素環芳香族環構造の炭素原子に結合したジカルボン酸である。官能性カルボキシル基の両方が同じ芳香族環に結合している必要はなく、２個以上の環がある場合は、これらを脂肪族または芳香族の２価の基、または−Ｏ−または−ＳＯ₂−などの２価の基によって結合することができる。
【００５９】
使用できる代表的な脂肪族および脂環式の酸には、セバチン酸、１，３−シクロヘキサンジカルボン酸、１，４−シクロヘキサンジカルボン酸、アジピン酸、グルタール酸、４−シクロヘキサン−１，２−ジカルボン酸、２−エチルスベリン酸、シクロペンタンジカルボン酸、デカヒドロ−１，５−ナフチレンジカルボン酸、４，４′−ビシクロヘキシルジカルボン酸、デカヒドロ−２，６−ナフチレンジカルボン酸、４，４′−メチレンビス（シクロヘキシル）カルボン酸、３，４−フランジカルボン酸がある。好ましい酸は、シクロヘキサン−ジカルボン酸およびアジピン酸である。
【００６０】
代表的な芳香族ジカルボン酸には、フタル酸、テレフタル酸、イソフタル酸、ビ安息香酸、ビス（ｐ−カルボキシフェニル）メタン、ｐ−オキシ−１，５−ナフタレンジカルボン酸、２，６−ナフタレンジカルボン酸、２，７−ナフタレンジカルボン酸、４，４，′−スルホニルジ安息香酸など２個のベンゼン環を有する置換ジカルボキシ化合物、ならびにそのＣ₁〜Ｃ₁₂アルキル誘導体、およびハロ、アルコキシおよびアリール誘導体などの環置換誘導体が含まれる。芳香族ジカルボン酸も存在するという条件でｐ−（β−ヒドロキシエトキシ）安息香酸などのヒドロキシ酸も使用することができる。
【００６１】
芳香族ジカルボン酸類が、本発明に有用なコポリエーテルエステルポリマーを調製するための好ましい種である。芳香族の酸の中では、炭素原子８〜１６個のものが好ましく、特にテレフタル酸単独またはフタル酸および／またはイソフタル酸との混合物が好ましい。
【００６２】
コポリエーテルエステルは、上記の式（ＩＩ）に相当する短鎖エステル単位約２５〜８０重量％を含有し、残りは上記の式（Ｉ）に相当する長鎖エステルである。コポリエーテルエステルが、約２５重量％未満の短鎖エステル単位しか含まないと、結晶化速度が非常に遅くなり、コポリエーテルエステルは粘着性で取り扱いが困難である。約８０重量％を超える短鎖エステル単位が存在すると、コポリエーテルエステルは一般に堅くなりすぎる。コポリエーテルエステルは、約３０〜６０重量％、好ましくは約４０〜６０重量％の短鎖エステル単位を含有し残りは長鎖エステル単位であることが好ましい。一般に、コポリエーテルエステル中の短鎖エステル単位の割合が高くなると、ポリマーの引張強さおよび弾性率が高くなり、水蒸気透過率は低下する。上記の式（Ｉ）および（ＩＩ）のＲによって表される基の少なくとも約７０％が１，４−フェニレン基であり、上記の式（ＩＩ）のＤによって表される基の少なくとも約７０％が１，４−ブチレン基であり、１，４−フェニレン基ではないＲ基および１，４−ブチレン基ではないＤ基の割合の合計が３０％を超えないことが最も好ましい。コポリエーテルエステルを作るために第２のジカルボン酸を使用する場合は、イソフタル酸が選択すべき酸であり、第２の低分子量ジオールを使用する場合は、１，４−ブテンジオールまたはヘキサメチレングリコールが選択すべきジオールである。
【００６３】
２つ以上のコポリエーテルエステルエラストマーのブレンドまたは混合物を使用することができる。ブレンドに用いる個々のコポリエーテルエステルエラストマーは、エラストマーについて本明細書ですでに開示した数値内に入れる必要はない。しかし、２つ以上のコポリエーテルエステルエラストマーのブレンドは、コポリエーテルエステルについて本明細書で説明した数値に、重量平均ベースで適合しなければならない。例えば、２つのコポリエーテルエステルエラストマーを等しい量含有する混合物において、短鎖エステル単位４５重量％の重量平均を得るために、１つのコポリエーテルエステルは６０重量％の短鎖エステル単位を含有することができ、もう１つのコポリエーテルエステルは３０重量％の短鎖エステル単位を含有することができる。
【００６４】
コポリエーテルエステルのＭＶＴＲは、様々な手段によって調節することができる。コポリエーテルエステル層の厚みはＭＶＴＲに影響し、層が薄いとＭＶＴＲは高くなる。コポリエーテルエステル中の短鎖エステル単位の割合が増加するとＭＶＴＲは低下するが、ポリマーの結晶性が高くなるために層の引張強さが増大することにもなる。
【００６５】
ＡＳＴＭ法Ｄ−４１２によって測定したコポリエーテルエステルエラストマーのヤング率は、好ましくは１０００〜１４，０００ｐｓｉ（６．８９〜９６．４６ＭＰａ）、通常２０００〜１０，０００ｐｓｉ（１３．７８〜６８．９ＭＰａ）である。弾性率は、コポリエーテルエステルエラストマーの短鎖セグメントと長鎖セグメントの比、およびコポリエーテルエステル調製用のコモノマーの選択によって制御することができる。弾性率が比較的低いコポリエーテルエステルは、一般に、構造の堅さとドレープが重要なラミネート構造に優れた引張回復性と美観をもたらす。
【００６６】
好ましくは、コポリエーテルエステルエラストマーは、テレフタル酸およびイソフタル酸のエステルまたはエステル混合物、１，４−ブタンジオール、およびポリ（テトラメチレンエーテル）グリコールまたはエチレンオキシドキャップドポリプロピレンオキシドグリコールから調製され、あるいは、テレフタル酸のエステル、例えばテレフタル酸ジメチル、１，４−ブタンジオール、およびポリ（エチレンオキシド）グリコールから調製される。より好ましくは、コポリエーテルエステルエラストマーは、テレフタル酸のエステル、例えばテレフタル酸ジメチル、１，４−ブタンジオール、およびポリ（エチレンオキシド）グリコールから調製される。
【００６７】
ジカルボン酸またはその誘導体および高分子量グリコールは、反応混合物中に存在するものと同じモル比で最終生成物に組み込まれる。実際に組み込まれる低分子量ジオールの量は、反応混合物中に存在する二塩基酸と高分子量グリコールのモル数の差に相当する。低分子量ジオールの混合物を用いる場合は、組み込まれる各ジオールの量は、主として、存在するジオールの量、これらの沸点、および相対的反応性の関数である。組み込まれるグリコールの総量は、やはり、二塩基酸と高分子グリコールのモル数の差である。本明細書に記載のコポリエーテルエステルエラストマーは、通常のエステル交換反応によって好都合に製造することができる。好ましい方法では、芳香族酸のエステル、例えばテレフタル酸のジメチルエステルを、ポリ（アルキレンオキシド）グリコールおよび過剰モルの低分子量ジオール、１，４−ブタンジオールとともに触媒存在下１５０°〜１６０℃に加熱し、次いで交換反応によって生成したメタノールを留去する。加熱はメタノールの発生が完結するまで継続する。温度、触媒、および過剰のグリコールに応じて、この重合は２〜３分から２〜３時間以内に完結する。この生成物は、低分子量プレポリマーの調製で終わり、これを以下に説明の方法によって高分子量コポリエーテルエステルにもってゆく。こうしたプレポリマーはまた、いくつかの他のエステル化またはエステル交換プロセスによって調製することもできる。例えば、長鎖グリコールを、高または低分子量短鎖エステルホモポリマーまたはコポリマーと、触媒の存在下ランダム化が起こるまで反応させることができる。短鎖エステルホモポリマーまたはコポリマーは、上記のようにジメチルエステルおよび低分子量ジオール、または遊離酸とジオール酢酸エステルからのエステル交換によって調製することができる。別法として、短鎖エステルコポリマーは、適当な酸、酸無水物、または酸塩化物と、例えばジオールとの直接エステル化によって、または酸と環状エステルまたはカーボネートの反応など他のプロセスによって調製することができる。明らかに、プレポリマーは、長鎖グリコールの存在下でこれらのプロセスを行わせることによっても調製することができる。
【００６８】
次いで、過剰の短鎖ジオールを蒸留することによって、得られるプレポリマーを高分子量にもってゆく。この方法は、「重縮合」として知られている。この蒸留中にエステル交換がさらに起こって、分子量が増大し、コポリエーテルエステル単位の配列がランダム化される。この最終蒸留または重縮合を、１，６−ビス−（３，５−ジ−ｔ−ブチル−４−ヒドロキシフェノール）プロピオンアミド］−ヘキサンまたは１，３，５−トリメチル−２，４，６−トリス［３，５−ジ−ｔ−ブチル−４−ヒドロキシベンジル］ベンゼンなどの酸化防止剤の存在下、圧力１ｍｍ未満および２４０°〜２６０℃で２時間未満行うと、通常最良の結果が得られる。重合反応を完結させるための最も実用的な重合技術としては、エステル交換が信頼できる。不可逆的な熱分解の恐れがある高温での過剰な保持時間を避けるために、エステル交換反応に触媒を使用することが有利である。様々な触媒を用いることができるが、チタン酸テトラブチルなどの有機チタン酸塩を単独でまたは酢酸マグネシウムまたは酢酸カルシウムと組み合わせて用いることが好ましい。アルカリまたはアルカリ土類金属アルコキシドとチタン酸エステルから誘導されるようなチタン酸錯体も非常に有効である。チタン酸ランタン、酢酸カルシウム／三酸化アンチモン混合物、ならびにリチウムおよびマグネシウムアルコキシドなどの無機チタン酸塩は、使用できるその他の触媒を代表するものである。
【００６９】
一般に、エステル交換重合は溶媒を加えないで溶融状態で行われるが、低温で反応混合物から揮発性成分を除去しやすくするために不活性溶媒を用いることができる。この技術は、例えば直接エステル化によるプレポリマーの調製時に特に貴重である。しかし、ある種の低分子量ジオール、例えばブタンジオールは、共沸蒸留によって重合中に都合よく除去される。他の特殊な重合技術、例えばビスフェノールとビスハロゲン化アシルおよびビスハロゲン化アシルキャップド線状ジオールとの界面重合は、特定のポリマーの調製に有用である。コポリエーテルエステルポリマー調製の任意の段階に、バッチ法および連続法のいずれをも用いることができる。プレポリマーの重縮合はまた、細分化した固形プレポリマーを真空中または不活性ガス流中で加熱して、遊離した低分子量ジオールを除去することによって固相でも行うことができる。この方法は、プレポリマーの軟化点未満の温度で行わねばならないので、分解を押さえる利点がある。主たる欠点は、所与の重合度に到達するのに長時間を要することである。
【００７０】
コポリエーテルエステルは多くの望ましい性質を有するが、熱または光による分解に対してもこれらの組成物を安定化させることが賢明なことがある。これは、コポリエーテルエステル組成物中に安定剤を混ぜることによって用意に実現できる。満足の行く安定剤は、フェノール、特にヒンダードフェノールおよびその誘導体、アミンおよびその誘導体、特にアリールアミンを含む。
【００７１】
安定剤として有用な代表的なフェノール誘導体には、４，４，′−ビス（２，６−ジ−ｔ−ブチルフェノール）；１，３，５−トリメチル−２，４，６−トリス［３，５−ジ−ｔ−ブチル−４−ヒドロキシベンジル］ベンゼン、および１，６−ビス［３，５−ジ−ｔ−ブチル−４−ヒドロキシフェニル）プロピオンアミド］ヘキサンが含まれる。ヒンダードフェノールとジラウリルチオジプロピオネートまたはホスフィットなどの補助安定剤との混合物が特に有用である。光安定性は、少量の顔料の添加、またはベンゾトリアゾール系紫外線吸収剤などの光安定剤の混合によって改良される。ビス（１，２，２，６，６−ペンタメチル−４−ピペリジニル）ｎ−ブチル−（３，５−ジ−ｔ−ブチル−４−ヒドロキシベンジル）マロネートなどのヒンダードアミン光安定剤を、通常、コポリエーテルエステルの０．０５〜１．０重量％の量で添加することは、耐光分解性を有する組成物の調製に特に有用である。
【００７２】
様々な通常のフィラーを、コポリエーテルエステルおよびフィラーのみの合計重量を基準として、一般に約１〜１０重量％の量でコポリエーテルエステルに加えることができる。クレー、タルク、アルミナ、カーボンブラック、およびシリカなどのフィラーを用いることができ、後者が好ましく、さらに白および淡色の顔料をポリマーに添加することができる。一般に、これらの添加剤は、様々な伸び率において弾性率を高くする効果がある。
【００７３】
本発明の方法によって得られるラミネート構造は、防水性および水蒸気透過性であり、コポリエーテルエステル含有層が基体に強く接着しているという利点がある。
【００７４】
本発明の方法によって得られるラミネート構造が、コポリエーテルエステル含有層と本明細書で既に説明したポリ（エチレン酢酸ビニル）を含む連結層とを含む場合は、ラミネート構造は、差別透過性を示すことができるというさらなる利点を有する。すなわち、ラミネート層を通る一方向のＭＶＴＲが、反対方向のＭＶＴＲより大きい。したがって、連結層を使用すると、接着性が改良されるだけでなく、コポリエーテルエステル含有層と組み合わせることで、その構造が差別透過性を示すようにすることができる。
【００７５】
差別透過性を示すようなラミネート構造では、コポリエーテルエステル含有層および連結層から基体方向へのＭＶＴＲ（下記の式（１）でＭＶＴＲ_CASとした）が、基体層から連結層およびコポリエーテルエステル含有層方向へのＭＶＴＲ（下記の式（１）でＭＶＴＲ_SACとした）より大きい。このＭＶＴＲ比は、下記のように表される。
【００７６】
ＭＶＴＲ_CAS／ＭＶＴＲ_SAC（式１）
【００７７】
好ましい実施形態では、ＭＶＴＲ比は、少なくとも約１．５、好ましくは約２から約１０である。
【００７８】
各層のＭＶＴＲは、主としてその層の化学組成および層の厚みの影響を受け、これらのパラメータを調整して、所望により、特定の最終用途に適するようにラミネートを仕立てることができる。
【００７９】
本発明の好ましい実施形態では、ＡＳＴＭ Ｅ９６−６６（ＢＷ法）による連結層のＭＶＴＲは、約１００から約２０００ｇｍ．ｍｉｌ／ｍ²／２４時間、好ましくは約１５０から約１５００ｇｍ．ｍｉｌ／ｍ²／２４時間であり；ＡＳＴＭ Ｅ９６−６６（ＢＷ法）によるコポリエーテルエステル含有層のＭＶＴＲは、少なくとも約２５００ｇｍ．ｍｉｌ／ｍ²／２４時間、好ましくは少なくとも約３５００ｇｍ．ｍｉｌ／ｍ²／２４時間、より好ましくは約３５００から約２００００ｇｍ．ｍｉｌ／ｍ²／２４時間である。
【００８０】
ラミネートに蒸気制御層としての機能を所望する場合は、上記の制御層を基体と連結層の間に加える。一般には、制御層を用いると、制御層を含むラミネート構造体のＭＶＴＲが、制御層のないラミネート構造体のＭＶＴＲよりも５から１０分の１、好ましくは２０分の１になる。
【００８１】
透過性は蒸気圧（相対湿度）と直線関係にない。相対湿度が上昇すると、コポリエーテルエステル含有層は、これを膨潤させ透過性を高くする組成で決まる量の水を吸収する。コポリエーテルエステルの水膨潤能力は、ポリマーの長鎖エステル単位の重量百分率が増加すると高くなる。
【００８２】
本発明の好ましい実施形態では、フィルム層が非常に薄くてもフィルム層と基体との間に良好な接着力が得られる。本発明の好ましい実施形態では、フィルム層が主としてコポリエーテルエステル、基体が主としてポリオレフィン繊維からなる不織布の場合、本発明のラミネート材料が少なくとも０．１Ｎ／ｍの接着強度を示すことが好ましい。より好ましくは、ラミネート材料の接着強度は少なくとも１Ｎ／ｍであり、より好ましくは少なくとも２Ｎ／ｍである。本発明のさらにより好ましい実施形態では、フィルム層が主として厚み５０μｍ未満のコポリエーテルエステル、基体が主としてポリオレフィン繊維からなる不織布の場合、フィルムと基体の接着強度は少なくとも３Ｎ／ｍ、より好ましくは少なくとも５Ｎ／ｍ、より好ましくは少なくとも８Ｎ／ｍ、最も好ましくは少なくとも１０Ｎ／ｍである。
【００８３】
本発明の方法で得られるラミネート構造体には多くの用途がある。このラミネートは防水性水蒸気透過性メンブレン、特に差別透過性を有するメンブレンであるメンブレンとして特に有用である。特に重要なのは、建設産業において、例えば屋根または壁下地材としてこれらを利用することである。このラミネートはまた、例えば、農業用マット、吸収性衛生製品、ガーメント、および手術用ドレープに用いる防水性で水蒸気透過性の織物の製造にも用いられる。こうした防水性で水蒸気透過性のガーメントは、ナイロンまたはポリエステルなどの基体を含むことができる。
【００８４】
次に図面について説明すると、図１では、連結層（２ａ）、熱可塑性ポリマー樹脂層（２ｂ）、および剥離層（３）が、押出機（１０）から基体（１）上に共押出される。コーティングされた基体は、ニップロール（１１）とチルロール（１２）の間でプレスされる。剥離層（３）は、リサイクルまたは廃棄のために分離ローラ（示さず）上へ剥ぎ取られ、ラミネート完成品（４）は他のローラ（示さず）上へ巻き取られる。
【００８５】
図２では、ラミネート構造体は、基体（５）、連結層（６）、および熱可塑性ポリマー樹脂コーティング（７）からなる。図２の矢印２０は、水蒸気透過の主たる方向である。矢印２１の方向へは、水蒸気の透過はほとんどまたはまったくない。
【００８６】
本発明を、以下の実施例によってさらに例証する。これらの実施例は例証を目的とするだけであり、上記の本発明を限定するものではないことを理解するであろう。本発明の精神から逸脱することなく、詳細の修正を行うことができる。
【００８７】
（実施例）
本発明の方法を、下記の実施例で例示する。一連のラミネートは、本発明の押出コーティング方法で引き剥がし可能な剥離層を用いて調製した。また、一連の比較例を引き剥がし可能な剥離層なしに調製した。
【００８８】
実施例において、基体はポリプロピレン（ＰＰ）不織布またはポリエチレン（ＰＥ）不織布であった。実施例で用いた基体は幅５５ｃｍであった。ＰＰ不織布基体は、坪量８５ｇ／ｍ²のＸａｖａｎ（登録商標）５２１７−Ｂスパンボンドポリプロピレンシート（イー・アイ・デュポン・ドゥ・ヌムール・アンド・カンパニー販売）であった。ＰＥ不織布は、坪量６０ｇ／ｍ²のＴｙｖｅｋ（登録商標）１４６０Ｂ（イー・アイ・デュポン・ドゥ・ヌムール・アンド・カンパニー販売）であった。ＥＬＶＡＸ（登録商標）３１７５（エチレン約７２％と酢酸ビニル約２８％を含むコポリマー、イー・アイ・デュポン・ドゥ・ヌムール・アンド・カンパニー販売）を含む連結層をいくつかの実施例で用いた。引き剥がし可能な剥離層は、ＬＤＰＥ（ＳＴＡＭＹＬＡＮ（登録商標）８１０８、ＤＳＭ販売）であった。
【００８９】
各実施例に用いたコポリエーテルエステル含有層は、ＡＣＴＩＶＥ ＭＥＭＢＲＡＮＥ ＡＭ６０００（登録商標）（イー・アイ・デュポン・ドゥ・ヌムール・アンド・カンパニー）であった。ＡＭ６０００（登録商標）は、１，４−ブチレンテレフタレート４５重量％、およびエチレンオキシド／プロピレンオキシドコポリエーテルテレフタレート５５重量％を含有する親水性コポリエーテルエステルである。コポリエーテルエステルの製造に用いたコポリ（アルキレンオキシド）グリコールは、ポリ（プロピレンエーテル）グリコールをエチレンオキシド６４重量％で末端キャッピングすることによって得られ、分子量は約２１００であった。コポリエーテルエステルは、エチレンオキシド含有量の計算値が３３重量％であり、短鎖エステル単位を４５重量％含有していた。このポリマーの融点は２００℃であった。樹脂は使用前に除湿乾燥機で（８０℃で８時間または２１０℃で２時間）乾燥した。
【００９０】
比較例１
ＡＭ６０００（登録商標）ポリマーのコポリエーテルエステルフィルムを、図１について既述したような押出ラミネーション装置を用いて上記のＰＰ不織布基体上に押出コーティングした。基体は、押出コーティング前に２ｋＷでコロナ処理した。コポリエーテルエステル樹脂はペレットの形状で、ＢＡＣ３層溶融物結合ブロックに接続された直径６４ｍｍ（２．５インチ）、４０ＨＰのスクリュー押出機に供給した。この比較例では、溶融物ブロックに供給されたポリマー溶融物はコポリエーテルエステルだけであった。コポリエーテルエステルポリマーは、溶融温度２５０℃で溶融物ブロックに供給された。この溶融物は、ダイギャップが０．７ｍｍで長さ７０５ｍｍのダイを通して溶融フィルムとして押し出された。この溶融フィルムは、接着剤をつけずにＰＰ不織布基体にコーティングされた。ＰＰ不織布基体は、ダイ開口部の下方に１５０ｍｍ離してあった。ＰＰ基体と溶融フィルム層を、直ちにチルロールとニップロールの間で加圧した。チルロールは、直径７５０ｍｍ、クロムメッキ、水冷（Ｔ_min＝８℃）ロールであり、ニップロールは、硬度８０ショアＡのシリコーンゴム表面を有するロールであった。ニップ圧は、２７ｋｇ／線ｃｍに保った。不織布は、１００ｍ／分のライン速度でニップに供給した。フィルムが回転チルロール上で冷えた後、ラミネートはトランスファーロールによってチルロールから取り出され引き取りロールに供給された。厚み２５μｍのフィルム層を有する基体が得られた。表１にまとめて示したように、基体とフィルム層との接着強度は無視できるほど小さかった。
【００９１】
比較例２
ＡＭ６０００（登録商標）ポリマーのコポリエーテルエステルフィルムを、厚み４０μｍのコポリエーテルエステルフィルム層が得られるようにポリマー溶融物の供給速度を上げたこと以外は比較例１の方法に従って、上記のＰＰ不織布基体上に押出コーティングした。下記の表１にまとめて示したように、基体とフィルム層との接着強度は無視できるほど小さかった。
【００９２】
比較例３
ＡＭ６０００（登録商標）ポリマーのコポリエーテルエステルフィルムを、下記のステップを追加して、比較例１の方法に従って上記のＰＰ不織布基体上に押出コーティングした。低密度ポリエチレン（ＤＳＭのＳＴＡＭＹＬＡＮ（登録商標）８１０８ＬＤＰＥ）は、やはりＢＡＣ３層溶融物結合ブロックに接続された直径９０ｍｍ（３．５インチ）、１５０ＨＰスクリュー押出機から押出された。ＬＤＰＥポリマーを、溶融温度２５０℃で溶融物ブロックに供給した。Ａ層としてコポリエーテルエステルおよびＢ層としてＬＤＰＥを有する２成分溶融フィルムをダイから押し出した。溶融フィルムを、フィルムのコポリエーテルエステル側をＰＰ基体に向けて、比較例１に記載のコロナ処理ＰＰ基体と接触させた。チルロールから取り出したラミネートは、厚み２５μｍのコポリエーテルエステルフィルム層と厚み２μｍのＬＤＰＥフィルム層を有していた。ＬＤＰＥフィルム層がコポリエーテルエステル層から引き剥がされ、ＰＰ基体／コポリエーテルエステルフィルムのラミネートが残った。表１にまとめて示したように、基体とフィルム層の間の接着強度は０．１９Ｎ／ｍであった。
【００９３】
実施例１
ＡＭ６０００（登録商標）ポリマーのコポリエーテルエステルフィルムを、厚み２０μｍのＬＤＰＥフィルム層が得られるようにＬＤＰＥポリマーの溶融物供給速度を上げたこと以外は比較例３の方法に従って、上記のＰＰ不織布基体上に押出コーティングした。下記の表１にまとめて示したように、この変化で、基体とフィルム層の間の接着強度は１０．４Ｎ／ｍに上昇した。
【００９４】
比較例４
ＡＭ６０００（登録商標）ポリマーのコポリエーテルエステルフィルムを、下記のステップを追加して、比較例１の方法に従って上記のＰＰ不織布基体上に押出コーティングした。ＥＶＡ連結層（ＥＬＶＡＸ（登録商標）３１７５、イー・アイ・デュポン・ドゥ・ヌムール・アンド・カンパニー）を、やはりＢＡＣ３層溶融物結合ブロックに接続された直径６４ｍｍ（２．５インチ）、４０ＨＰのスクリュー押出機から押し出した。ＥＶＡポリマーを、溶融温度２４０℃で溶融物ブロックに供給した。Ａ層としてコポリエーテルエステルおよびＣ層としてＬＤＰＥを有する２成分溶融フィルムをダイから押し出した。溶融フィルムを、フィルムのＥＶＡ側をＰＰ基体に向けて、比較例１に記載のコロナ処理したＰＰ基体と接触させた。チルロールから取り出したラミネートは、コポリエーテルエステル層とＰＰ基体の間に厚み２５μｍのコポリエーテルエステルフィルム層と厚み３μｍのＥＶＡフィルム連結層を有していた。表１にまとめて示したように、基体とフィルム層の間の接着強度は２．３Ｎ／ｍであった。
【００９５】
比較例５
ＡＭ６０００（登録商標）ポリマーのコポリエーテルエステルフィルムを、下記のステップを追加して、比較例４の方法に従って上記のＰＰ不織布基体上に押出コーティングした。低密度ポリエチレン（ＤＳＭのＳＴＡＭＹＬＡＮ（登録商標）８１０８ＬＤＰＥ）は、やはりＢＡＣ３層溶融物結合ブロックに接続された直径８．９ｃｍ（３．５インチ）、１５０ＨＰスクリュー押出機から押出された。ＬＤＰＥポリマーを、溶融温度２５０℃で溶融物ブロックに供給した。片側のＬＤＰＥ層Ｂと反対側のＥＶＡ層Ｃとの間にコポリエーテルエステル層Ａを挟んだ３成分溶融フィルムをダイから押し出した。溶融フィルムを、フィルムのＥＶＡ側をＰＰ基体に向けて、比較例１に記載のコロナ処理したＰＰ基体と接触させた。チルロールから取り出したラミネートは、厚み３μｍのＥＶＡフィルム層がＰＰ基体と厚み２５μｍのコポリエーテルエステルフィルム層の間に接着していた。厚み２μｍのＬＤＰＥフィルム層が、コポリエーテルエステル層の反対側に接着していた。ＬＤＰＥフィルム層がコポリエーテルエステル層から引き剥がされ、ＰＰ基体／ＥＶＡフィルム／コポリエーテルエステルフィルムのラミネートが残った。表１にまとめて示したように、基体とフィルム層の間の接着強度は３．６Ｎ／ｍであった。
【００９６】
実施例２
ＡＭ６０００（登録商標）ポリマーのコポリエーテルエステルフィルムを、厚み２０μｍのＬＤＰＥフィルム層が得られるようにＬＤＰＥポリマーの溶融物供給速度を上げたこと以外は比較例５の方法に従って、上記のコロナ処理したＰＰ不織布基体上に押出コーティングした。表１にまとめて示したように、この変化で、基体とフィルム層の間の接着強度は、フィルムが基体から剥離する前にポリマーフィルムが破壊したほどであった。ＡＳＴＭ Ｄ１００４に従って測定したポリマーフィルムの引裂抵抗は、１００Ｎ／ｍを超える。
【００９７】
実施例２のラミネートのＭＶＴＲ比を、引き剥がし可能な剥離層を除去して以下のように測定した。標準試験ＮＦ Ｇ５２（温度３２℃で「アップカップ」法）を用いて、基体を湿気に向けたＭＶＴＲは１０７６ｇｍ／ｍ²／２４時間を示し、コポリエーテルエステル含有層を湿気に向けたＭＶＴＲは２３２８ｇｍ／ｍ²／２４時間を示した。ＭＶＴＲ比はしたがって２．１６である。
【００９８】
比較例６
ＡＭ６０００（登録商標）ポリマーのコポリエーテルエステルフィルムを、コロナ処理したＰＥ不織布基体（Ｔｙｖｅｋ（登録商標）１４６０Ｂ、イー・アイ・デュポン・ドゥ・ヌムール・アンド・カンパニー販売）をＰＰ不織布基体の代わりに用いたこと以外は比較例１の方法に従って、不織布基体上に押出コーティングした。表１にまとめて示したように、基体とフィルム層の間の接着強度は無視できるほど小さかった。
【００９９】
実施例３
ＡＭ６０００（登録商標）ポリマーのコポリエーテルエステルフィルムを、コロナ処理したＰＥ不織布基体（Ｔｙｖｅｋ（登録商標）１４６０Ｂ、イー・アイ・デュポン・ドゥ・ヌムール・アンド・カンパニー販売）をＰＰ不織布基体の代わりに用いたこと以外は比較例３の方法に従って、不織布基体上に押出コーティングした。表１にまとめて示したように、基体とフィルム層の間の接着強度は２．２Ｎ／ｍであった。
【０１００】
実施例４
ＡＭ６０００（登録商標）ポリマーのコポリエーテルエステルフィルムを、以下の変化を除いて、比較例６の方法に従って不織布基体上に押出コーティングした。コロナ処理したＰＥ不織布基体（Ｔｙｖｅｋ（登録商標）１４６０Ｂ、イー・アイ・デュポン・ドゥ・ヌムール・アンド・カンパニー販売）をＰＰ不織布基体の代わりに用いた。さらに、ＥＬＶＡＸ（登録商標）連結層の厚みを、実施例２の３μｍ厚フィルム層の代わりに４μｍ厚フィルム層として押出した。表１にまとめて示したように、この変化で、基体とフィルム層の間の接着強度は、フィルムが基体から剥離する前にＴＹＶＥＫ（登録商標）基体が破壊したほどであった。
【０１０１】
標準試験ＩＳＯ２４１１に従って、上記実施例に記載のラミネート各々の接着強度を測定した。結果を表１にまとめて示す。
【０１０２】
【表１】

【０１０３】
表１に示した試験データから、本発明の方法は、ポリマーコーティングの厚みが非常に薄い場合でも、ポリマーコーティングと基体の間の接着性が良好なラミネートを提供できることがわかる。
以下に、本発明の好ましい態様を示す。
［１］ その表面に熱可塑性ポリマー樹脂コーティングを有する基体を含み、前記熱可塑性ポリマー樹脂の基体から離れた表面と接触している引き剥がし可能な剥離層をさらに含むラミネートを調製する方法であって、前記方法が、
基体層を形成するまたは設けるステップと、
その表面に熱可塑性ポリマー樹脂コーティングおよび引き剥がし可能な剥離層を設けるステップとを含み、引き剥がし可能な剥離層は、熱可塑性ポリマー樹脂コーティングの厚みの少なくとも３０％の厚みであり、熱可塑性ポリマー樹脂は、ＩＳＯ１１４４３規格に従って、１０から１０，０００ｓｅｃ^-1で、最低は熱可塑性ポリマー樹脂の融点のすぐ上の温度から最高は熱可塑性ポリマー樹脂の加工温度のすぐ上の温度で測定した粘度が約３０００Ｐａ．ｓ未満であることを特徴とする方法。
［２］ 前記熱可塑性ポリマー樹脂コーティングおよび前記引き剥がし可能な剥離層が前記基体上に共押出される共押出方法であることを特徴とする［１］に記載の方法。
［３］ １０から１０，０００ｓｅｃ^-1で熱可塑性ポリマー樹脂の融点より２０から４０℃高い温度で、ＩＳＯ１１４４３規格に従って測定した前記熱可塑性ポリマー樹脂の粘度が、約３０００Ｐａ．ｓ未満であることを特徴とする［２］に記載の方法。
［４］ ＩＳＯ１１４４３規格に従って測定した前記熱可塑性ポリマー樹脂の粘度が、約４０から約１０００Ｐａ．ｓであることを特徴とする［１］に記載の方法。
［５］ 前記剥離層を取り外し、任意選択で前記引き剥がし可能な剥離層をリサイクルするステップをさらに含むことを特徴とする［１］に記載の方法。
［６］ 前記熱可塑性ポリマー樹脂コーティングの厚みが、約５０μｍ未満であることを特徴とする［１］に記載の方法。
［７］ 前記引き剥がし可能な剥離層の厚みが、前記熱可塑性ポリマー樹脂コーティングの厚みより薄いことを特徴とする［１］に記載の方法。
［８］ 前記引き剥がし可能な剥離層が、ポリエチレンまたはポリプロピレンを含むことを特徴とする［１］に記載の方法。
［９］ 連結層を前記熱可塑性ポリマー樹脂とともに共押出するステップをさらに含むことを特徴とする［１］に記載の方法。
［１０］ 前記連結層の厚みが、前記熱可塑性ポリマー樹脂層の厚みより薄いことを特徴とする［９］に記載の方法。
［１１］ 前記基体が、ポリオレフィンを含むことを特徴とする［１］に記載の方法。
［１２］ 前記熱可塑性層が、１つまたは複数のコポリエーテルエステルエラストマーを含むことを特徴とする［１］に記載の方法。
［１３］ その表面に熱可塑性ポリマー樹脂コーティングを有する基体を含み、前記熱可塑性ポリマー樹脂の基体から離れた表面と接触している引き剥がし可能な剥離層をさらに含むラミネートを調製する方法であって、前記方法が、
基体層を形成するまたは設けるステップと、
その表面に熱可塑性ポリマー樹脂コーティングおよび引き剥がし可能な剥離層を設けるステップとを含み、引き剥がし可能な剥離層は、熱可塑性ポリマー樹脂コーティングの厚みの少なくとも３０％の厚みであり、熱可塑性ポリマー樹脂は、ＩＳＯ１１４４３規格に従って、１０から１０，０００ｓｅｃ^-1で、最低は熱可塑性ポリマー樹脂の融点のすぐ上の温度から最高は熱可塑性ポリマー樹脂の加工温度のすぐ上の温度で測定した粘度が約３０００Ｐａ．ｓ未満である方法であって、
前記熱可塑性ポリマー樹脂が１つまたは複数のコポリエーテルエステルエラストマーを含み、前記コポリエーテルエステルエラストマーが、エステル結合で頭尾結合した複数の反復長鎖エステル単位および短鎖エステル単位を有し、前記長鎖エステル単位が次式によって表され、
【化３】

前記短鎖エステル単位が次式によって表され、
【化４】

式中、
Ｇが、平均分子量が約４００〜３５００のポリ（アルキレンオキシド）グリコールから末端水酸基を除去した後に残る２価の基であり、ポリ（アルキレンオキシド）グリコールによって前記１つまたは複数のコポリエーテルエステルに組み込まれたエチレンオキシド基の量は、コポリエーテルエステルの総重量を基準にして約２５から約６８重量％であり、
Ｒが、分子量が約３００未満のジカルボン酸からカルボキシル基を除去した後に残る２価の基であり、
Ｄが、分子量が約２５０未満のジオールから水酸基を除去した後に残る２価の基であり、
前記コポリエーテルエステルが、約２５から約８０重量％の短鎖エステル単位を含有することを特徴とする方法。
［１４］ 前記基体がポリオレフィンを含み、前記連結層がエチレンと酢酸ビニルのコポリマーを含み、前記熱可塑性ポリマー樹脂が１つまたは複数のコポリエーテルエステルを含むことを特徴とする［９］または［１０］に記載の方法。
［１５］ ＭＶＴＲ_CASが前記コポリエーテルエステル含有層および前記連結層から前記基体方向への水蒸気透過率（ＭＶＴＲ）であり、ＭＶＴＲ_SACが前記基体層から前記連結層および前記コポリエーテルエステル含有層方向へのＭＶＴＲである場合に、得られたラミネートはＭＶＴＲ_CAS＞ＭＶＴＲ_SACであることを特徴とする［１４］に記載の方法。
［１６］ ＭＶＴＲ比がＭＶＴＲ_CAS／ＭＶＴＲ_SACとして定義され、得られたラミネートは少なくとも約１．５のＭＶＴＲを有することを特徴とする［１５］に記載の方法。
［１７］ ２５ミクロンの厚さの試験片で、ＡＳＴＭ Ｅ９６−６６（ＢＷ法）による前記連結層の前記水蒸気透過率（ＭＶＴＲ）が、約１００から約２０００ｇ／ｍ²／２４時間であることを特徴とする［１４］に記載の方法。
［１８］ ２５ミクロンの厚さの試験片で、ＡＳＴＭ Ｅ９６−６６（ＢＷ法）によるコポリエーテルエステル含有層の前記水蒸気透過率（ＭＶＴＲ）が、少なくとも約２５００ｇ／ｍ²／２４時間であることを特徴とする［１２］または１３に記載の方法。
［１９］ 得られたラミネートで、ＩＳＯ２４１１に従って測定した基体層と前記熱可塑性ポリマー樹脂の間の接着強度が、少なくとも１Ｎ／ｍであることを特徴とする［５］または［９］に記載の方法。
［２０］ 得られたラミネートで前記熱可塑性ポリマー樹脂コーティングの厚みが約３５μｍ未満であり、かつ前記基体層と前記ポリマー樹脂コーティングの間の接着強度が少なくとも３Ｎ／ｍであることを特徴とする［１４］に記載の方法。
［２１］ 防水性水蒸気透過性メンブレンとしての、［１］または［１４］に記載の方法によって得ることができるラミネートの使用。
【図面の簡単な説明】
【図１】 ３層ラミネート構造体を製造するための、本発明の共押出方法を示す概略図である。
【図２】 本発明の方法によって得られる３層ラミネート構造体の断面図である。[0001]
This application claims the benefit of priority of provisional application No. 60 / 156,167, filed Sep. 27, 1999.
[0002]
(Background of the Invention)
Field of Invention
The present invention relates to a method for producing a laminate comprising a substrate and a polymer coating, in particular a thin polymer coating, in particular an extrusion coating method. In particular, the present invention further relates to a method of making a laminate product useful in medical, apparel, hygiene, agriculture, and construction applications, such as garments, diapers or roofing substrates.
[0003]
Explanation of related technology
Methods for extrusion melt coating polymer resins, such as polyurethane, polyamide, or polyester resins, onto nonwoven or other substrates are well known. In general, the method involves heating the polymer to a temperature above its melting point, extruding it through a flat die onto a substrate that passes through a curtain of molten polymer, and pressurizing and bonding the coated substrate. And then cooling. The extrusion melt coating method is widely used because a laminate structure can be economically produced in a one-step method.
[0004]
In some cases, the polymer resin layer can form a bond to the substrate without the need for additional adhesives or primers between the substrate and the polymer resin layer. In other cases, sufficient adhesion can only be obtained by separately applying an adhesive or primer to the substrate. Alternatively, a “tie layer” as a compatibilizer is coextruded with the polymer coating to adhere the polymer coating to the substrate.
[0005]
However, disadvantages remain with the extrusion melt coating process. In particular, certain polymer resin and substrate combinations provide a strong bond between the polymer resin and the substrate such that the laminate product has high delamination resistance, even with the use of additional adhesives, primers, or tie layers. It is not enough to make sure. This is especially true when it is desired to produce a laminate having a thin polymer resin layer.
[0006]
One reason for the poor adhesion of certain incompatible polymer resin and substrate combinations, especially when thin films are required, is that the polymer resin coating cools rapidly when it comes into contact with the substrate surface. It appears that there is not enough time to act and form a strong bond. In general, the adhesion between an incompatible polymer resin coating and a substrate, such as a polyester coating and a polyethylene substrate, consists primarily of mechanical bonds and little chemical bonds. In general, to ensure good bonding, the polymer resin coating must penetrate deep enough into the substrate structure.
[0007]
Furthermore, conventional extrusion melting methods may not be suitable for the manufacture of products that require thin polymer coatings. As mentioned above, the polymer resin coating cools too quickly when it comes into contact with the substrate, which may cause the polymer coating to solidify before forming a layer of uniform thickness.
[0008]
Another disadvantage of the extrusion melt coating method is that it tends to form pinholes in the polymer layer. For example, to ensure that the laminate structure is waterproof, it is important to prevent pinholes and provide a continuous coating layer. Since the substrate is generally made of a coarse or porous material, pinholes are generated. During extrusion coating and subsequent pressurization, the molten thermoplastic resin enters the pores and gaps of the substrate, and as a result, the thermoplastic resin film can be broken by undulations and fibrous protrusions on the substrate surface. In order to produce thin polymer resin coatings, the occurrence of pinholes is a particular problem, and in order to avoid the occurrence of pinholes in such coatings, it is generally necessary for the polymer resin to penetrate shallowly into the substrate. Therefore, it is a challenge to obtain a thin polymer coating without pinholes that adheres strongly to the substrate.
[0009]
One way to minimize the problem of poor adhesion and pinhole generation is to thicken the polymer resin layer. If the resin layer is thicker, it seems that there is an effect of maintaining the temperature at the interface between the polymer resin and the substrate, so that a stronger bond could be formed. Furthermore, if the resin layer is thick, it will be less likely to be divided by the unevenness of the substrate, and thus pinholes will be less likely to occur.
[0010]
However, increasing the thickness of the polymer resin layer is economically disadvantageous and is not always appropriate depending on the end use of the product. As noted above, it may be desirable for the laminate product to include a thin polymer film layer. For example, in the case of a water vapor permeable laminate, the water vapor transmission rate decreases as the thickness increases. The laminate structure is also used as a waterproof material or a water vapor permeable membrane, for example, in the production of packaging materials, fabrics, medical materials, packaging materials and the like. Thickening the resin layer of such a laminate to minimize pinholes and achieve adequate waterproofing will lose the desirable properties of the nonwoven. A laminate suitable for such applications consists of, for example, a polyethylene resin coating on a nonwoven fabric substrate. The thickness of the resin layer of such a laminate must be at least 40 μm, preferably 60 μm or more in order to prevent the occurrence of pinholes. For this reason, the laminate structure is hard to bend and becomes hard, reducing the value of the product. .
[0011]
European Patent EP-A 0611037 discloses a method for producing a laminate that can be used in protective clothing, diapers, and roofing substrates. In this method, a water vapor permeable, liquid impervious barrier layer having a thickness of 3 to 25 μm is coextruded with a release layer having a thickness of 1 to 5 μm on one side of the barrier layer and a connecting layer having a thickness of 1 to 5 μm on the opposite side of the barrier layer. . The connecting layer is bonded to a porous substrate such as a woven fabric or a nonwoven fabric. In general, the tie layer includes a thermoplastic resin such as ethylene copolymer or polyurethane and serves to improve the adhesion between the porous substrate and the breathable thermoplastic barrier layer.
[0012]
European Patent EP-A 0295694 discloses an extrusion melt coating process for producing a waterproof, water vapor permeable laminate. This patent is directed to the problem of obtaining sufficient water resistance without generating pinholes while maintaining desirable properties of the substrate material. The thermoplastic polymer resin used to prepare this laminate has a melt viscosity of at least 5000 Pa.s at a temperature 20-30 ° C. below the extrusion temperature. It is necessary to be s, and this makes it possible to produce a thermoplastic resin film having a thickness of 5 to 30 μm. It has been reported that if a resin that does not satisfy this viscosity condition is used, pinholes are generated. The extruder heating temperature is such that the melt viscosity of the resin immediately after being extruded from the die is 100 to 1000 Pa.s. It is set to be in the range of s. Resins that meet this very temperature dependent viscosity profile are reported to be relatively unstable in the extrusion process. Thus, in the manufacture of the laminate structure of EP-A 0295694, an additional “release layer” (generally polyethylene or polypropylene) that can be peeled off from the first thermoplastic resin layer is used as the first thermoplastic resin. And coextrusion. The release layer is then peeled off after cooling to obtain the desired structure.
[0013]
Japanese Patent Application Laid-Open No. 01-71742 discloses a laminate used as a medical waterproof sheet, a surgical clothing fabric, or a windbreaker fabric comprising a porous substrate and a thermoplastic resin layer having a thickness of 5 to 30 μm. In this patent, the thermoplastic resin layer has a melt viscosity of at least 50000 poise at a temperature 20 ° C. below the extrusion temperature. The method of manufacturing this laminate also uses coextrusion of a thermoplastic resin layer and an additional release layer.
[0014]
This prior art relates to laminates made with a polymer having a specific minimum viscosity, and the problems encountered when it is necessary to utilize a low viscosity polymer to produce a very thin film on a substrate. Not targeted. In general, when the viscosity is below a certain level, the molten polymer will flow into the gaps and pores of the substrate fairly easily, and when the polymer coating is a thin layer coating, there is good adhesion strength between the thin polymer layer and the substrate. If necessary, pinholes are more likely to occur. These prior art processes also do not address the problem of improving the adhesion between the incompatible polymer resin and the substrate layer. There remains a need for an economical process to produce a laminate structure with good adhesion between a very thin polymer resin layer and a substrate layer.
[0015]
The main object of the present invention is a laminate with good adhesion between the polymer resin and the substrate layer, in particular a laminate comprising a low viscosity polymer resin, and in particular strong adhesion when using conventional lamination or extrusion coating methods. It is to provide an improved method for producing a laminate comprising a combination of a polymer resin and a substrate that does not occur. Another object of the present invention is to provide a method for producing a laminate having a thin polymer resin layer bonded to the resin layer with good adhesive strength without forming holes in the resin layer. Another object of the present invention is to provide a method for producing a waterproof, water vapor permeable laminate, particularly a laminate having differential permeability.
[0016]
(Definition)
As used herein, the term “polymer” generally includes, but is not limited to, homopolymers, copolymers (eg, block, graft, random, and alternating copolymers, etc.), terpolymers, and the like, and blends thereof. Modified products are included. Further, unless otherwise specifically limited, the term “polymer” is intended to include all possible geometries of materials. These configurations include, but are not limited to, isotactic, syndiotactic, and random symmetries.
[0017]
As used herein, the term “polyolefin” is intended to mean any series of polymeric hydrocarbons that are generally saturated and consist solely of carbon and hydrogen. Exemplary polyolefins include, but are not limited to, polyethylene, polypropylene, polymethylpentene, and various combinations of ethylene, propylene, and methylpentene monomers.
[0018]
As used herein, the term “polyethylene” is intended to include not only homopolymers of ethylene but also copolymers in which at least 85% of the repeating units are ethylene units.
[0019]
As used herein, the term “polypropylene” is intended to include not only homopolymers of propylene but also copolymers in which at least 85% of the repeating units are propylene units.
[0020]
As used herein, the term “nonwoven fabric, sheet or web” means a structure consisting of individual fibers or threads that are randomly arranged to form a planar material without a discernable pattern, such as a knitted fabric. .
[0021]
(Detailed explanation)
According to the present invention, a method of preparing a laminate comprising a substrate having a thermoplastic polymer resin coating on its surface and further having a peelable release layer in contact with a surface remote from the thermoplastic polymer resin substrate. The method comprising forming or providing a substrate layer and providing a thermoplastic polymer resin coating and a peelable release layer on the surface, the thermoplastic polymer resin being measured according to ISO 11443 standard The viscosity is about 3000 Pa. A method is provided that is less than s.
[0022]
In a preferred embodiment, the thermoplastic polymer resin preferably consists primarily of block polyether copolymers such as polyetherester copolymers, polyetheramide copolymers, polyurethane copolymers, polyvinyl alcohol, or combinations thereof. A preferred copolyetherester block copolymer is a segmented elastomer having soft polyether segments and hard polyester segments, as disclosed in US Pat. No. 4,739,012 (assigned to DuPont). A suitable polyetherester block copolymer is sold by DuPont under the name Hytrel®. Hytrel (registered trademark) is a registered trademark of DuPont. Suitable copolyether amide copolymers are available from Atochem Inc. of Glen Rock, NJ, USA. Is a copolyamide marketed under the name Pebax®. Pebax (R) is a trademark of Elf Atochem, S.A., Paris, France. A is a registered trademark of A. A suitable polyurethane is B. Cleveland, Ohio, USA. It is a thermoplastic urethane sold under the name Estane (R) by the F Goodrich Company. In a more preferred embodiment, the thermoplastic polymer resin comprises one or more copolyetherester elastomers, and the invention is described below for this embodiment.
[0023]
Methods for preparing this laminate can include conventional techniques well known in the art. However, this method is advantageously a coextrusion method. In this co-extrusion method, each layer is co-extruded simultaneously through individual orifices of a multi-orifice die, and then the layers that are still molten are merged or, preferably, the melt stream of each polymer is formed into a die manifold. Each layer is coextruded onto the substrate by single channel coextrusion that is first coalesced in channels leading to, and then extruded together from the die orifice onto the substrate without mixing in laminar flow conditions. This method may include, for example, laminating a preformed polymer coating layer and a preformed release layer and laminating it with a substrate, or performing these laminations simultaneously, or, for example, a preformed copolymer Conventional lamination techniques can be included, such as casting a release layer onto the ether ester-containing layer. Generally, such lamination technology uses thermal lamination of each layer in a hot roll calender facility, and the temperature used to adhere the copolyetherester containing layer to the substrate melts the copolyetherester containing layer. Although the release layer does not melt, it is sufficient to apply sufficient pressure to bond these layers. A combination of extrusion and lamination techniques can also be used.
[0024]
This method is preferably an extrusion coating method in which a release layer is coextruded with the copolyetherester-containing layer.
[0025]
The method of the present invention comprises a laminate comprising a combination of a copolyetherester-containing layer and a substrate, particularly a laminate comprising a combination of a copolyetherester coating and a substrate that does not adhere strongly using conventional lamination or extrusion coating methods. Has the advantage of enabling. This method is particularly useful for the manufacture of laminates having a thin polymer resin layer. This method is also useful in the manufacture of waterproof vapor permeable laminates, particularly laminates having differential permeability.
[0026]
The method of the present invention is useful for the preparation of laminates comprising a thin copolyetherester-containing layer, in particular a layer having a thickness of less than about 100 μm, in particular less than about 70 μm, in particular less than about 50 μm, in particular less than about 30 μm and in particular less than about 20 μm. . The copolyetherester-containing layer is preferably at least 5 μm, more preferably at least 12 μm.
[0027]
In order to avoid doubt, the order between each layer is described: the copolyetherester-containing layer is adjacent to the substrate, and the peelable release layer is the copolyetherester-containing layer on the surface away from the substrate. Adjacent to the inclusion layer.
[0028]
The substrate is any woven or nonwoven material, preferably a nonwoven material, more preferably a spunbond material. In one embodiment of the invention, the substrate comprises at least 50% by weight, in particular at least 65% by weight, in particular at least 90% by weight and in particular at least 99% by weight of polyolefins, in particular polyethylene or polypropylene. Polyolefins can contain small amounts of other comonomer units, but are those containing at least 50% by weight, in particular at least 65% by weight, in particular at least 90% by weight and in particular at least 99% by weight of olefin repeat units. In one embodiment, at least 50% by weight, in particular at least 65% by weight, in particular at least 90% by weight and in particular at least 99% by weight of the fibers are polyolefin fibers. In other embodiments, the substrate is any such that the bond strength as defined by ISO 2411 is typically less than 1 N / m when attached to the copolyetherester by mechanical and / or chemical adhesion in a conventional manner. Material. As used herein, the term “spunbond material” means a nonwoven fabric formed by filaments that have been extruded, stretched, and then placed on a continuous belt. Bonding is accomplished by several methods, such as hot roll calendering or passing the web through a saturated steam chamber at high pressure. An example of a spunbond nonwoven useful in the present invention is Typar® spunbond polypropylene sold by EI DuPont de Nemours & Company.
[0029]
In one embodiment of the invention, the method further comprises providing a tie layer between the copolyetherester-containing layer and the substrate. The tie layer serves to further improve the adhesion of the copolyetherester polymer coating to the substrate. In other words, the tie layer can compatibilize the substrate and the copolyetherester polymer, forming a strong bond to both the substrate and the copolyetherester polymer. In a preferred embodiment, the tie layer comprises one or more copolymers of ethylene and vinyl acetate, preferably about 30 to about 90% by weight, preferably about 60 to about 85% by weight, preferably about 67 to about 77% by weight. As well as copolymers comprising from about 10 to about 70% by weight, preferably from about 15 to about 40% by weight, more preferably from about 23 to about 33% by weight vinyl acetate comonomer units. A commercially available material of this type is ELVAX® (EVA sold by EI DuPont de Nemours & Company). If the above amounts of ethylene and vinyl acetate units are present, other comonomer units may be present in small amounts in the copolymer. Such a tie layer is particularly useful when the substrate comprises a polyolefin and the thermoplastic polymer resin comprises one or more copolyetheresters.
[0030]
This tie layer can further comprise conventional additives known in the art. The amount of the copolymer comprising ethylene and vinyl acetate present in the tie layer is preferably at least 80%, more preferably at least 85%, more preferably at least 95%, and most preferably substantial, of the tie layer. 100% by weight.
[0031]
When providing a tie layer, the thickness is preferably less than the thickness of the copolyetherester-containing layer, preferably from about 1 μm to about 20 μm, preferably from about 2 μm to about 8 μm, and even more preferably from about 2 μm to about 6 μm. is there.
[0032]
Optionally, the laminate can include a control layer disposed between the substrate and the tie layer, wherein the control layer includes a polymer that can reduce the moisture vapor transmission rate (MVTR) of the laminate. If such a layer has the effect of reducing the MVTR of the laminate and the control layer is compatible with both the substrate and the tie layer, there are no particular restrictions on the polymers that can be used for the control layer. Examples of suitable polymers include polyethylene or polypropylene, or copolymers thereof containing ethylene and / or propylene as the main repeating unit. The general thickness of the control layer is 2 to 15 μm, preferably 10 to 15 μm.
[0033]
In another embodiment of the present invention, the method includes adding an additional adhesive or primer to the substrate before applying the copolyetherester-containing layer to the substrate surface, or before applying the copolyetherester-containing layer and the linking layer to the substrate surface. The method further includes providing the surface.
[0034]
The method of the present invention optionally includes one or more steps of removing the release layer, either online following the cooling of the laminate, or at a later stage after laminate transport, and recycling the release layer removed from the laminate. In addition.
[0035]
The peelable release layer needs to have peelability from the copolyetherester-containing layer, and is preferably coextrudable with the copolyetherester-containing layer. An important requirement of the peelable release layer is that its viscosity should be approximately the same as that of the copolyetherester at the processing temperature used in the manufacture of the laminate. The peelable release layer generally comprises a polymer resin, in particular polyethylene or polypropylene, or a copolymer thereof comprising ethylene and / or propylene as the main repeating unit. In a preferred embodiment, the release layer comprises low density polyethylene (LDPE). An example of a suitable LDPE is STAMYLAN® 8108 (from DSM).
[0036]
The thickness of the peelable release layer depends on the thickness of the copolyetherester-containing layer. It is important that the peelable release layer is sufficiently thick to ensure that the copolyetherester-containing layer penetrates sufficiently into the substrate structure. It is also important that the peelable release layer be sufficiently thick so that it can be peeled from the copolyetherester-containing layer. However, if the release layer is too thick, pinholes are generated. It has been found that the thickness of the release layer should be less than the thickness of the copolyetherester-containing layer. Preferably, the thickness of the release layer should be no more than about 90%, even more preferably no more than about 80% of the thickness of the copolyetherester-containing layer. Preferably, the thickness of the release layer is at least 5%, preferably at least 15%, preferably at least 30% of the thickness of the copolyetherester-containing layer. In other words, T_RLThe thickness of the release layer, T_CLIs the thickness of the copolyetherester-containing layer, T_RL/ T_CLShould be less than 1, preferably less than about 0.9, more preferably less than about 0.8. Preferably T_RL/ T_CLIs greater than about 0.05, preferably greater than about 0.15, and preferably greater than about 0.3. In a preferred embodiment, T_RL/ T_CLIs about 0.8.
[0037]
For example, in one embodiment of the present invention, the thickness of the copolyetherester-containing layer is about 30 μm. Accordingly, the thickness of the peelable release layer should be less than about 30 μm, preferably less than about 27 μm and at least 15 μm, preferably about 24 μm.
[0038]
The peelable release layer achieves one or more of the following effects.
(A) During the coating process, it can serve as a temperature control and thus a thermal control layer to control the flow of the polymer coating. In other words, the release layer provides additional heat capacity to the polymer coating layer, which allows the coating layer to stay at a higher temperature for a longer time and therefore to melt longer. This long duration of the molten state appears to provide additional time for the polymer to flow into the interstices of the substrate and improve mechanical adhesion. In some cases, this additional heat can initiate or enhance melting of the polymer resin-substrate interface to increase the bond strength. By changing the thickness and composition of the release layer and its temperature, the cooling time and flow of the polymer coating can be adjusted, and as a result, the adhesive strength between the polymer resin and the substrate can be further controlled. Let's go. This makes it possible to further control the coating quality, particularly with respect to the flatness of the thickness of the thermoplastic polymer resin layer, and makes it possible to produce a more uniform laminate.
(B) For example, to reduce fouling of the copolyetherester-containing layer later in the manufacturing process or during transport, or to reduce adhesion of the copolyetherester-containing layer to equipment during subsequent processing, where it is not desired It can serve as a protective layer.
(C) As an additional benefit of reducing unwanted attachment of the copolyetherester-containing layer to the facility, the process can be operated at higher speeds, typically 100 m / min, often at least 150 m / min. .
(D) Can play a role in reducing pinholes, bubbles, and other defects in the polymer coating. If the polymer coating is still too "soft" during the process step using pressurization of the coated substrate (eg, by calender roll), the nip pressure can push air into the coating resulting in pinholes. This is created by air pockets or bubbles entrained and pressurized during the coating process and then ruptured in the coated substrate. The use of a peelable release layer can prevent air pockets from entering the coating, thus allowing for the production of a more uniform laminate.
[0039]
Of course, the present invention is not intended to be limited by the theory described in (a) to (d) above.
[0040]
The copolyetherester-containing layer, based on the weight of the polymer of this layer, comprises at least 50% by weight of copolyetherester, preferably at least 65% by weight, preferably at least 80% by weight, more preferably at least 90% by weight, in particular Contains at least 99% by weight. Copolyetheresters are generally hydrophilic as described in detail below.
[0041]
The viscosity of the copolyetherester measured according to the ISO 11443 standard is about 3000 Pa. s, preferably at least 20 Pa.s. s. The viscosity measured according to ISO 11443 standard is preferably from about 20 to about 2000 Pa.s. s, more preferably from about 40 to about 1000 Pa.s. s, more preferably from about 50 to about 700 Pa.s. s. Viscosity Pa. s is the shear rate sec^-1And as a function of temperature, measured according to the ISO 11443 standard. The temperature used for viscosity measurement is from a minimum just above the melting (or softening) point of the polymer (generally about 200 to about 210 ° C.) and the maximum is a processing method for thermoplastic materials (eg, coextrusion, injection molding, and lamination). ) (Generally about 230 to about 260 ° C., especially about 240 to about 250 ° C.). Generally, the temperature used in the processing of the thermoplastic resin is about 20 to about 50 ° C., and particularly about 40 to about 50 ° C. above the melting point of the thermoplastic resin. The shear rate used for viscosity measurement is about 10 to about 10,000 sec.^-1Met. This range includes shear rates commonly used in thermoplastic material processing methods.
[0042]
In one embodiment of the invention, the viscosity of the copolyetherester is about 3000 Pa.s as measured according to the ISO 11443 standard at a temperature range of about 200 to about 250 ° C. s, preferably at least 20 Pa.s. s, preferably from about 20 to about 2000 Pa.s. s, more preferably from about 40 to about 1000 Pa.s. s, more preferably from about 50 to about 700 Pa.s. s. In another embodiment, the viscosity of the copolyetherester is about 3000 Pa.s, measured according to the ISO 11443 standard at a temperature 20 to 35 ° C. below the processing temperature used in the method of the invention. s, preferably at least 20 Pa.s. s, preferably from about 20 to about 2000 Pa.s. s, more preferably from about 40 to about 1000 Pa.s. s, more preferably from about 50 to about 700 Pa.s. s. In this embodiment, the meaning of “processing temperature used in the method of the present invention” is preferably the extrusion temperature used in the preferred coextrusion coating method of the present invention.
[0043]
Preferably, the melting point of the copolyetherester is above 120 ° C, usually from about 120 ° C to about 220 ° C. When the melting point of the copolyetherester is below about 120 ° C., the polymer is sticky and difficult to handle in the form of a film, and when the melting point is above about 220 ° C., the film becomes too stiff. The melting point is measured by differential scanning calorimetry (DSC) according to the ISO 3146 standard.
[0044]
In one embodiment of the present invention, the copolyetherester elastomer is selected from those disclosed in US Pat. No. 4,725,481. This disclosure is incorporated herein by reference.
[0045]
In a preferred embodiment, the copolyetherester elastomer has a plurality of repeating long-chain ester units and short-chain ester units head-to-tail bonded with ester bonds, wherein the long-chain ester units are represented by the formula:
[0046]
[Chemical Formula 3]

[0047]
The short chain ester unit is represented by the following formula:
[0048]
[Formula 4]

[0049]
Where
G is a divalent group remaining after removal of the terminal hydroxyl group from poly (alkylene oxide) glycol having an average molecular weight of about 400-3500, and is incorporated into the one or more copolyetheresters by poly (alkylene oxide) glycol The amount of ethylene oxide groups removed is from about 20 to about 68% by weight, preferably from about 25 to about 68% by weight, based on the total weight of the copolyetherester;
R is a divalent group remaining after removing a carboxyl group from a dicarboxylic acid having a molecular weight of less than about 300;
D is a divalent group remaining after removal of the hydroxyl group from a diol having a molecular weight of less than about 250;
The copolyetherester contains about 25 to about 80% by weight of short chain ester units.
[0050]
The copolyetherester has an MVTR according to ASTM E 96-66 (BW method) of at least about 2500, preferably at least about 3500, more preferably from about 3500 to about 20000 gm. mil / m²/ 24 hours are preferred.
[0051]
As used herein, the term “ethylene oxide group incorporated into a copolyetherester” refers to (CH₂-CH₂-O-) means the weight percent of the total copolyetherester. The ethylene oxide groups of the copolyetherester that are counted to determine the amount in the polymer are derived from poly (alkylene oxide) glycols and not the ethylene oxide groups introduced into the copolyetherester by low molecular weight diols.
[0052]
As used herein, the term “long chain ester unit” as applied to units in a polymer chain refers to the reaction product of a long chain glycol and a dicarboxylic acid. Suitable long chain glycols are poly (alkylene oxide) glycols having a hydroxyl group at the end (or as close to the end as possible) and a molecular weight of about 400 to about 3500, especially about 600 to about 1500.
[0053]
The poly (alkylene oxide) glycol used in the preparation of the copolyetherester is from about 20 to about 68 wt%, preferably from about 25 to about 68 wt%, more preferably from about 30 based on the total weight of the copolyetherester. A copolyetherester having about 55% by weight of ethylene oxide groups is the amount that contains ethylene oxide groups. The ethylene oxide group gives the polymer the property of allowing water vapor to easily permeate, and generally the water permeability increases when the ratio of ethylene oxide in the copolyetherester is high. A random or block copolymer of ethylene oxide containing a small amount of a second poly (alkylene oxide) glycol can be used. In general, when present, the second monomer should comprise less than about 30 mole percent, usually less than about 20 mole percent of the poly (alkylene oxide) glycol. Exemplary long chain glycols include poly (ethylene oxide) glycol, ethylene oxide capped polypropylene oxide glycol, poly (ethylene oxide) glycol, provided that the resulting copolyetherester has an amount of ethylene oxide groups of at least about 25% by weight. Mixtures with other glycols such as ethylene oxide capped poly (propylene oxide) glycol and / or poly (tetramethylene oxide) glycol are included. Copolyetheresters prepared from poly (ethylene oxide) glycol having a molecular weight of about 600 to 1500 are preferred because they have both excellent water vapor permeability and limited water swellability, and are useful in a wide temperature range when formed into films. Show properties.
[0054]
The term “short chain ester unit” as applied to a polymer chain unit of a copolyetherester refers to a low molecular weight compound or polymer chain unit having a molecular weight of less than about 550. These are prepared by reacting a low molecular weight diol or mixture of diols (MW less than about 250) with a dicarboxylic acid to form ester units represented by the above formula (II).
[0055]
Low molecular weight diols that react to form short chain ester units suitable for use in preparing copolyetheresters include acyclic, alicyclic, and aromatic dihydroxy compounds. Preferred compounds are ethylene glycol, propylene glycol, isobutylene glycol, tetramethylene glycol, 1,4-pentamethylene glycol, 2,2-dimethyltrimethylene glycol, hexamethylene glycol and decamethylene glycol, dihydroxycyclohexane, cyclohexanedimethanol, resorcinol Diols having 2 to 15 carbon atoms, such as hydroquinone and 1,5-dihydroxynaphthalene. Particularly preferred diols are aliphatic diols containing 2 to 8 carbon atoms, and most preferred is 1,4-butanediol. Bisphenols that can be used include bis (p-hydroxy) diphenyl, bis (p-hydroxyphenyl) methane, and bis (p-hydroxyphenyl) propane. Equivalent diol derivatives that form esters are also useful (eg, ethylene oxide or ethylene carbonate can be used as an alternative to ethylene glycol). As used herein, the term “low molecular weight diol” should be construed to include such equivalent ester-forming derivatives. However, molecular weight requirements are associated with diols, not derivatives.
[0056]
The dicarboxylic acid that reacts with the long-chain glycol and the low molecular weight diol to form a copolyetherester is an aliphatic, alicyclic, or aromatic dicarboxylic acid having a low molecular weight, that is, a molecular weight of less than about 300. As used herein, the term “dicarboxylic acid” refers to the acid equivalent of a dicarboxylic acid having a bifunctional carboxyl group that functions substantially like a dicarboxylic acid when reacted with a glycol and diol to form a copolyetherester polymer. Including things. These equivalents include esters and ester-forming derivatives such as acid halides and acid anhydrides. The molecular weight requirement is associated with the acid and not with its equivalent ester or ester-forming derivative. Thus, an ester of a dicarboxylic acid having a molecular weight greater than 300 or an acid equivalent of a dicarboxylic acid having a molecular weight greater than 300 is included if the molecular weight of the acid is less than about 300. The dicarboxylic acid can include any substituent or combination that does not substantially interfere with the formation of the copolyetherester polymer and the use of the polymer in the compositions of the present invention.
[0057]
As used herein, the term “aliphatic dicarboxylic acid” means a carboxylic acid having two carboxyl groups each bonded to a saturated carbon atom. The acid is alicyclic when the carbon atom to which the carboxyl group is attached is saturated and cyclic. An aliphatic acid or alicyclic acid having a conjugated unsaturated bond is often not usable because it homopolymerizes. However, certain unsaturated acids such as maleic acid can be used.
[0058]
As used herein, the term aromatic dicarboxylic acid is a dicarboxylic acid in which two carboxyl groups are bonded to carbon atoms of a carbocyclic aromatic ring structure. It is not necessary for both functional carboxyl groups to be bonded to the same aromatic ring, and if there are two or more rings, these can be aliphatic or aromatic divalent groups, or -O- or -SO₂It can be bonded by a divalent group such as-.
[0059]
Typical aliphatic and cycloaliphatic acids that can be used include sebacic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, glutaric acid, 4-cyclohexane-1,2-dicarboxylic acid. Acid, 2-ethylsuberic acid, cyclopentanedicarboxylic acid, decahydro-1,5-naphthylenedicarboxylic acid, 4,4'-bicyclohexyldicarboxylic acid, decahydro-2,6-naphthylenedicarboxylic acid, 4,4'- There are methylenebis (cyclohexyl) carboxylic acid and 3,4-furandicarboxylic acid. Preferred acids are cyclohexane-dicarboxylic acid and adipic acid.
[0060]
Typical aromatic dicarboxylic acids include phthalic acid, terephthalic acid, isophthalic acid, bibenzoic acid, bis (p-carboxyphenyl) methane, p-oxy-1,5-naphthalenedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid. Substituted dicarboxy compounds having two benzene rings such as acid, 2,7-naphthalenedicarboxylic acid, 4,4, '-sulfonyldibenzoic acid, and C₁~ C₁₂Alkyl derivatives and ring substituted derivatives such as halo, alkoxy and aryl derivatives are included. Hydroxy acids such as p- (β-hydroxyethoxy) benzoic acid can also be used provided that an aromatic dicarboxylic acid is also present.
[0061]
Aromatic dicarboxylic acids are the preferred species for preparing the copolyetherester polymers useful in the present invention. Among the aromatic acids, those having 8 to 16 carbon atoms are preferable, and terephthalic acid alone or a mixture with phthalic acid and / or isophthalic acid is particularly preferable.
[0062]
The copolyetherester contains about 25 to 80% by weight of short chain ester units corresponding to the above formula (II), with the remainder being long chain esters corresponding to the above formula (I). If the copolyetherester contains less than about 25% by weight of short chain ester units, the crystallization rate is very slow, and the copolyetherester is sticky and difficult to handle. If there are more than about 80% by weight of short chain ester units, the copolyetherester is generally too stiff. The copolyetherester preferably contains about 30-60% by weight, preferably about 40-60% by weight of short chain ester units, with the remainder being long chain ester units. In general, as the proportion of short chain ester units in the copolyetherester increases, the tensile strength and elastic modulus of the polymer increase and the water vapor transmission rate decreases. At least about 70% of the groups represented by R in the above formulas (I) and (II) are 1,4-phenylene groups, and at least about 70% of the groups represented by D in the above formula (II) Is a 1,4-butylene group, and it is most preferable that the sum of the proportions of R groups that are not 1,4-phenylene groups and D groups that are not 1,4-butylene groups does not exceed 30%. If a second dicarboxylic acid is used to make the copolyetherester, isophthalic acid is the acid to be selected, and if a second low molecular weight diol is used, 1,4-butenediol or hexamethylene glycol Is the diol to be selected.
[0063]
A blend or mixture of two or more copolyetherester elastomers can be used. The individual copolyetherester elastomers used in the blend need not be within the values already disclosed herein for the elastomer. However, a blend of two or more copolyetherester elastomers must meet the numerical values described herein for the copolyetherester on a weight average basis. For example, in a mixture containing equal amounts of two copolyetherester elastomers, one copolyetherester may contain 60 wt% short chain ester units to obtain a weight average of 45 wt% short chain ester units. Another copolyetherester can contain 30% by weight of short chain ester units.
[0064]
The MVTR of the copolyetherester can be adjusted by various means. The thickness of the copolyetherester layer affects the MVTR, and the thinner the layer, the higher the MVTR. Increasing the proportion of short-chain ester units in the copolyetherester decreases MVTR, but also increases the tensile strength of the layer due to higher polymer crystallinity.
[0065]
The Young's modulus of the copolyetherester elastomer measured by ASTM method D-412 is preferably 1000-14,000 psi (6.89-96.46 MPa), usually 2000-10,000 psi (13.78-68.9 MPa). is there. The modulus of elasticity can be controlled by the ratio of the short and long chain segments of the copolyether ester elastomer and the choice of comonomer for preparing the copolyether ester. Copolyetheresters with relatively low modulus generally provide excellent tensile recovery and aesthetics for laminate structures where structural stiffness and drape are important.
[0066]
Preferably, the copolyetherester elastomer is prepared from an ester or ester mixture of terephthalic acid and isophthalic acid, 1,4-butanediol, and poly (tetramethylene ether) glycol or ethylene oxide capped polypropylene oxide glycol, or terephthalic acid Esters, such as dimethyl terephthalate, 1,4-butanediol, and poly (ethylene oxide) glycol. More preferably, the copolyetherester elastomer is prepared from an ester of terephthalic acid, such as dimethyl terephthalate, 1,4-butanediol, and poly (ethylene oxide) glycol.
[0067]
The dicarboxylic acid or derivative thereof and the high molecular weight glycol are incorporated into the final product in the same molar ratio as present in the reaction mixture. The amount of low molecular weight diol actually incorporated corresponds to the difference in the number of moles of dibasic acid and high molecular weight glycol present in the reaction mixture. When using a mixture of low molecular weight diols, the amount of each diol incorporated is primarily a function of the amount of diol present, their boiling point, and relative reactivity. The total amount of glycol incorporated is again the difference in the number of moles of dibasic acid and polymeric glycol. The copolyetherester elastomers described herein can be conveniently prepared by conventional transesterification reactions. In a preferred method, an ester of an aromatic acid, such as dimethyl ester of terephthalic acid, is heated to 150 ° -160 ° C. in the presence of a catalyst with poly (alkylene oxide) glycol and an excess molar low molecular weight diol, 1,4-butanediol. Then, the methanol produced by the exchange reaction is distilled off. Heating is continued until the generation of methanol is complete. Depending on the temperature, catalyst, and excess glycol, the polymerization is complete within 2-3 minutes to 2-3 hours. This product ends with the preparation of a low molecular weight prepolymer, which is brought into a high molecular weight copolyetherester by the method described below. Such prepolymers can also be prepared by several other esterification or transesterification processes. For example, long chain glycols can be reacted with high or low molecular weight short chain ester homopolymers or copolymers in the presence of a catalyst until randomization occurs. Short chain ester homopolymers or copolymers can be prepared by transesterification from dimethyl esters and low molecular weight diols or free acids and diol acetates as described above. Alternatively, short chain ester copolymers may be prepared by direct esterification of a suitable acid, anhydride, or acid chloride with, for example, a diol, or by other processes such as the reaction of an acid with a cyclic ester or carbonate. Can do. Obviously, prepolymers can also be prepared by performing these processes in the presence of long chain glycols.
[0068]
The resulting prepolymer is then brought to high molecular weight by distilling excess short chain diol. This method is known as “polycondensation”. Further transesterification occurs during this distillation, increasing the molecular weight and randomizing the arrangement of the copolyetherester units. This final distillation or polycondensation is carried out using 1,6-bis- (3,5-di-tert-butyl-4-hydroxyphenol) propionamide] -hexane or 1,3,5-trimethyl-2,4,6- Best results are usually obtained when carried out in the presence of an antioxidant such as tris [3,5-di-t-butyl-4-hydroxybenzyl] benzene at a pressure of less than 1 mm and less than 2 hours at 240 ° -260 ° C. . Transesterification is reliable as the most practical polymerization technique for completing the polymerization reaction. It is advantageous to use a catalyst in the transesterification reaction in order to avoid excessive holding times at high temperatures that can cause irreversible pyrolysis. Various catalysts can be used, but organic titanates such as tetrabutyl titanate are preferably used alone or in combination with magnesium acetate or calcium acetate. Titanate complexes such as those derived from alkali or alkaline earth metal alkoxides and titanates are also very effective. Lanthanum titanate, calcium acetate / antimony trioxide mixtures, and inorganic titanates such as lithium and magnesium alkoxides represent other catalysts that can be used.
[0069]
In general, the transesterification polymerization is performed in a molten state without adding a solvent, but an inert solvent can be used to facilitate removal of volatile components from the reaction mixture at a low temperature. This technique is particularly valuable when preparing prepolymers, for example by direct esterification. However, certain low molecular weight diols such as butanediol are conveniently removed during polymerization by azeotropic distillation. Other specialized polymerization techniques such as interfacial polymerization of bisphenols with bisacyl halides and bisacyl halide-capped linear diols are useful for the preparation of certain polymers. Both batch and continuous processes can be used at any stage in the preparation of the copolyetherester polymer. The polycondensation of the prepolymer can also be carried out in the solid phase by heating the fragmented solid prepolymer in a vacuum or in an inert gas stream to remove free low molecular weight diols. This method has the advantage of suppressing degradation because it must be performed at a temperature below the softening point of the prepolymer. The main drawback is that it takes a long time to reach a given degree of polymerization.
[0070]
Copolyetheresters have many desirable properties, but it may be advisable to stabilize these compositions against thermal or light degradation. This can be readily accomplished by mixing a stabilizer in the copolyetherester composition. Satisfactory stabilizers include phenols, especially hindered phenols and their derivatives, amines and their derivatives, especially arylamines.
[0071]
Representative phenol derivatives useful as stabilizers include 4,4, '-bis (2,6-di-tert-butylphenol); 1,3,5-trimethyl-2,4,6-tris [3, 5-di-t-butyl-4-hydroxybenzyl] benzene and 1,6-bis [3,5-di-t-butyl-4-hydroxyphenyl) propionamide] hexane. Particularly useful are mixtures of hindered phenols and co-stabilizers such as dilauryl thiodipropionate or phosphite. The light stability is improved by adding a small amount of pigment or mixing a light stabilizer such as a benzotriazole-based UV absorber. Hindered amine light stabilizers such as bis (1,2,2,6,6-pentamethyl-4-piperidinyl) n-butyl- (3,5-di-t-butyl-4-hydroxybenzyl) malonate are usually copolyols. The addition of 0.05 to 1.0% by weight of the ether ester is particularly useful for the preparation of a composition having photodegradation resistance.
[0072]
Various conventional fillers can be added to the copolyetherester, generally in an amount of about 1 to 10% by weight, based on the total weight of the copolyetherester and filler alone. Fillers such as clay, talc, alumina, carbon black, and silica can be used, the latter being preferred, and white and light pigments can be added to the polymer. In general, these additives have the effect of increasing the elastic modulus at various elongation rates.
[0073]
The laminate structure obtained by the method of the present invention is waterproof and water vapor permeable, and has the advantage that the copolyetherester-containing layer is strongly adhered to the substrate.
[0074]
If the laminate structure obtained by the method of the present invention comprises a copolyetherester-containing layer and a tie layer comprising poly (ethylene vinyl acetate) as previously described herein, the laminate structure exhibits differential permeability. Has the additional advantage of being able to That is, the MVTR in one direction through the laminate layer is larger than the MVTR in the opposite direction. Thus, the use of a tie layer not only improves adhesion but also allows the structure to exhibit differential permeability when combined with a copolyetherester-containing layer.
[0075]
In a laminate structure exhibiting differential permeability, the MVTR from the copolyetherester-containing layer and the linking layer toward the substrate (MVTR in the following formula (1))_CASMVTR from the substrate layer to the linking layer and the copolyetherester-containing layer direction (MVTR in the following formula (1))_SACAnd larger) This MVTR ratio is expressed as follows.
[0076]
MVTR_CAS/ MVTR_SAC(Formula 1)
[0077]
In preferred embodiments, the MVTR ratio is at least about 1.5, preferably from about 2 to about 10.
[0078]
The MVTR of each layer is primarily influenced by the chemical composition of the layer and the thickness of the layer, and these parameters can be adjusted to tailor the laminate to suit a particular end use if desired.
[0079]
In a preferred embodiment of the present invention, the MVTR of the tie layer according to ASTM E96-66 (BW method) is about 100 to about 2000 gm. mil / m²/ 24 hours, preferably from about 150 to about 1500 gm. mil / m²MVTR of the copolyetherester-containing layer according to ASTM E96-66 (BW method) is at least about 2500 gm. mil / m²/ 24 hours, preferably at least about 3500 gm. mil / m²/ 24 hours, more preferably from about 3500 to about 20000 gm. mil / m²/ 24 hours.
[0080]
If the laminate functions as a vapor control layer, the control layer is added between the substrate and the tie layer. In general, when a control layer is used, the MVTR of the laminate structure including the control layer is 5 to 1/10, preferably 1/20, than the MVTR of the laminate structure without the control layer.
[0081]
Permeability is not linearly related to vapor pressure (relative humidity). As the relative humidity increases, the copolyetherester-containing layer absorbs an amount of water determined by a composition that swells and increases permeability. The water swelling ability of the copolyetherester increases as the weight percentage of the long chain ester units of the polymer increases.
[0082]
In a preferred embodiment of the present invention, good adhesion is obtained between the film layer and the substrate even if the film layer is very thin. In a preferred embodiment of the present invention, it is preferred that the laminate material of the present invention exhibits an adhesive strength of at least 0.1 N / m when the film layer is a non-woven fabric mainly composed of copolyetherester and the substrate is mainly composed of polyolefin fibers. More preferably, the adhesive strength of the laminate material is at least 1 N / m, more preferably at least 2 N / m. In an even more preferred embodiment of the present invention, when the film layer is a copolyetherester mainly having a thickness of less than 50 μm and the substrate is a nonwoven fabric mainly consisting of polyolefin fibers, the adhesive strength between the film and the substrate is at least 3 N / m, more preferably at least 5 N. / M, more preferably at least 8 N / m, most preferably at least 10 N / m.
[0083]
The laminate structure obtained by the method of the present invention has many uses. This laminate is particularly useful as a waterproof water vapor permeable membrane, in particular a membrane having differential permeability. Of particular importance is their use in the construction industry, for example as a roof or wall substrate. This laminate is also used in the manufacture of waterproof, water vapor permeable fabrics for use in, for example, agricultural mats, absorbent hygiene products, garments, and surgical drapes. Such waterproof, water vapor permeable garments can include a substrate such as nylon or polyester.
[0084]
Referring now to the drawings, in FIG. 1, a tie layer (2a), a thermoplastic polymer resin layer (2b), and a release layer (3) are coextruded from an extruder (10) onto a substrate (1). . The coated substrate is pressed between nip roll (11) and chill roll (12). The release layer (3) is stripped onto a separation roller (not shown) for recycling or disposal, and the finished laminate (4) is wound onto another roller (not shown).
[0085]
In FIG. 2, the laminate structure consists of a substrate (5), a tie layer (6), and a thermoplastic polymer resin coating (7). The arrow 20 in FIG. 2 is the main direction of water vapor transmission. In the direction of arrow 21, there is little or no water vapor transmission.
[0086]
The invention is further illustrated by the following examples. It will be understood that these examples are for illustrative purposes only and are not intended to limit the invention as described above. Modification of detail may be made without departing from the spirit of the invention.
[0087]
(Example)
The method of the present invention is illustrated in the following examples. A series of laminates were prepared using a release layer that was peelable by the extrusion coating method of the present invention. Also, a series of comparative examples were prepared without a peelable release layer.
[0088]
In the examples, the substrate was a polypropylene (PP) nonwoven or polyethylene (PE) nonwoven. The substrate used in the examples was 55 cm wide. PP nonwoven fabric base weight is 85g / m²Xavan (registered trademark) 5217-B spunbond polypropylene sheet (sold by EI DuPont de Nemours and Company). PE nonwoven fabric has a basis weight of 60g / m²Tyvek (registered trademark) 1460B (sold by EI DuPont de Nemours and Company). A tie layer comprising ELVAX® 3175 (a copolymer comprising about 72% ethylene and about 28% vinyl acetate, sold by EI DuPont de Nemours and Company) was used in some examples. The peelable peelable layer was LDPE (STAMYLAN (registered trademark) 8108, sold by DSM).
[0089]
The copolyetherester-containing layer used in each example was ACTIVE MEMBRANE AM6000 (registered trademark) (Ei Dupont de Nemours and Company). AM6000® is a hydrophilic copolyether ester containing 45% by weight of 1,4-butylene terephthalate and 55% by weight of ethylene oxide / propylene oxide copolyether terephthalate. The copoly (alkylene oxide) glycol used to make the copolyetherester was obtained by end-capping poly (propylene ether) glycol with 64% by weight of ethylene oxide and had a molecular weight of about 2100. The copolyetherester had a calculated ethylene oxide content of 33% by weight and contained 45% by weight of short chain ester units. The melting point of this polymer was 200 ° C. The resin was dried in a dehumidifying dryer (8 hours at 80 ° C. or 2 hours at 210 ° C.) before use.
[0090]
Comparative Example 1
A co-polyetherester film of AM6000® polymer was extrusion coated onto the PP nonwoven substrate using an extrusion lamination apparatus as previously described for FIG. The substrate was corona treated at 2 kW before extrusion coating. The copolyetherester resin was supplied in the form of pellets to a screw extruder with a diameter of 64 mm (2.5 inches) and 40 HP connected to a BAC three-layer melt bond block. In this comparative example, the only polymer melt fed to the melt block was copolyetherester. The copolyetherester polymer was fed to the melt block at a melt temperature of 250 ° C. This melt was extruded as a molten film through a die having a die gap of 0.7 mm and a length of 705 mm. This molten film was coated on a PP nonwoven substrate without adhesive. The PP nonwoven substrate was 150 mm apart below the die opening. The PP substrate and molten film layer were immediately pressed between chill roll and nip roll. The chill roll has a diameter of 750 mm, chrome plating, water cooling (T_min= 8 ° C.) and the nip roll was a roll having a silicone rubber surface with a hardness of 80 Shore A. The nip pressure was kept at 27 kg / line cm. The nonwoven fabric was fed into the nip at a line speed of 100 m / min. After the film cooled on a rotating chill roll, the laminate was removed from the chill roll by a transfer roll and fed to a take-up roll. A substrate having a film layer with a thickness of 25 μm was obtained. As summarized in Table 1, the adhesive strength between the substrate and the film layer was negligibly small.
[0091]
Comparative Example 2
According to the method of Comparative Example 1, except that the AM6000 (registered trademark) polymer copolyetherester film was fed at a higher polymer melt feed rate so as to obtain a 40 μm thick copolyetherester film layer. Extrusion coated on top. As summarized in Table 1 below, the adhesive strength between the substrate and the film layer was negligibly small.
[0092]
  Comparative Example 3
  An AM6000® polymer copolyetherester film was extrusion coated onto the PP nonwoven substrate according to the method of Comparative Example 1 with the following additional steps. Low density polyethylene (DSM's STAMMYLAN® 8108LDPE) was extruded from a 90 mm (3.5 inch) diameter, 150 HP screw extruder, also connected to a BAC three layer melt bond block. The LDPE polymer was fed to the melt block at a melt temperature of 250 ° C. A two component melt film having a copolyetherester as layer A and LDPE as layer B was extruded from a die. The molten film was contacted with the corona-treated PP substrate described in Comparative Example 1 with the copolyetherester side of the film facing the PP substrate. The laminate taken out from the chill roll had a 25 μm thick copolyetherester film layer and a 2 μm thick LDPE film layer. The LDPE film layer was peeled away from the copolyetherester layer, leaving a PP substrate / copolyetherester film laminate. As summarized in Table 1, the adhesive strength between the substrate and the film layer was 0.19 N / m.
[0093]
  Example 1
  The AM6000 (registered trademark) polymer copolyetherester film, except that the LDPE polymer melt feed rate was increased so that a 20 μm thick LDPE film layer was obtained.Comparative Example 3According to the above method, extrusion coating was carried out on the above-mentioned PP nonwoven fabric substrate. As summarized in Table 1 below, this change increased the bond strength between the substrate and the film layer to 10.4 N / m.
[0094]
  Comparative Example 4
  An AM6000® polymer copolyetherester film was extrusion coated onto the PP nonwoven substrate according to the method of Comparative Example 1 with the following additional steps. A screw with a diameter of 64 mm (2.5 inches), 40 HP, connected to an EVA tie layer (ELVAX® 3175, EI Dupont de Nemours & Company), also to a BAC three-layer melt bond block Extruded from the extruder. EVA polymer was fed to the melt block at a melt temperature of 240 ° C. A two-component melt film having copolyetherester as layer A and LDPE as layer C was extruded from the die. The molten film was contacted with a corona-treated PP substrate as described in Comparative Example 1 with the EVA side of the film facing the PP substrate. The laminate taken out from the chill roll had a 25 μm thick copolyetherester film layer and a 3 μm thick EVA film connecting layer between the copolyetherester layer and the PP substrate. As summarized in Table 1, the adhesive strength between the substrate and the film layer was 2.3 N / m.
[0095]
  Comparative Example 5
  The AM6000® polymer copolyetherester film is added with the following steps:Comparative Example 4Was extrusion coated onto the above PP nonwoven substrate. Low density polyethylene (DSM's STAMMYLAN® 8108LDPE) was extruded from a 8.9 cm (3.5 inch), 150 HP screw extruder, also connected to a BAC three layer melt bond block. The LDPE polymer was fed to the melt block at a melt temperature of 250 ° C. A three-component molten film in which the copolyetherester layer A was sandwiched between the LDPE layer B on one side and the EVA layer C on the opposite side was extruded from the die. The molten film was contacted with a corona-treated PP substrate as described in Comparative Example 1 with the EVA side of the film facing the PP substrate. In the laminate taken out from the chill roll, the EVA film layer having a thickness of 3 μm was adhered between the PP substrate and the copolyetherester film layer having a thickness of 25 μm. A 2 μm thick LDPE film layer was adhered to the opposite side of the copolyetherester layer. The LDPE film layer was peeled away from the copolyetherester layer, leaving a PP substrate / EVA film / copolyetherester film laminate. As summarized in Table 1, the adhesive strength between the substrate and the film layer was 3.6 N / m.
[0096]
  Example 2
  The AM6000 (registered trademark) polymer copolyetherester film, except that the LDPE polymer melt feed rate was increased so that a 20 μm thick LDPE film layer was obtained.Comparative Example 5According to the above method, the above-mentioned corona-treated PP non-woven fabric substrate was extrusion coated. As summarized in Table 1, with this change, the adhesive strength between the substrate and the film layer was such that the polymer film broke before the film peeled off the substrate. The tear resistance of the polymer film, measured according to ASTM D1004, exceeds 100 N / m.
[0097]
  Example 2The MVTR ratio of the laminate was measured as follows after removing the peelable release layer. Using a standard test NF G52 (“up cup” method at a temperature of 32 ° C.), the MVTR with the substrate facing moisture was 1076 gm / m²MVTR showing 24 hours and the copolyetherester-containing layer facing moisture is 2328 gm / m²/ 24 hours. The MVTR ratio is therefore 2.16.
[0098]
  Comparative Example 6
  AM6000® polymer copolyetherester film with corona-treated PE nonwoven substrate (Tyvek® 1460B, sold by EI DuPont de Nemours & Co.) instead of PP nonwoven substrate Except for the above, it was extrusion coated onto the nonwoven fabric substrate according to the method of Comparative Example 1. As summarized in Table 1, the adhesive strength between the substrate and the film layer was negligibly small.
[0099]
  Example 3
  AM6000 (registered trademark) polymer copolyetherester film using corona-treated PE nonwoven substrate (Tyvek (registered trademark) 1460B, sold by Ei DuPont de Nemours and Company) instead of PP nonwoven substrate Except thatComparative Example 3Was extrusion coated onto a nonwoven substrate. As summarized in Table 1, the adhesive strength between the substrate and the film layer was 2.2 N / m.
[0100]
  Example 4
  The AM6000® polymer copolyetherester film, except for the following changes:Comparative Example 6Was extrusion coated onto a nonwoven substrate according to A corona-treated PE nonwoven substrate (Tyvek® 1460B, sold by EI DuPont de Nemours & Company) was used in place of the PP nonwoven substrate. Furthermore, the thickness of the ELVAX (registered trademark) coupling layer isExample 2The film was extruded as a 4 μm thick film layer instead of the 3 μm thick film layer. As summarized in Table 1, with this change, the adhesive strength between the substrate and the film layer was such that the TYVEK® substrate broke before the film peeled off the substrate.
[0101]
According to standard test ISO 2411, the adhesive strength of each of the laminates described in the above examples was measured. The results are summarized in Table 1.
[0102]
[Table 1]

[0103]
  From the test data shown in Table 1, it can be seen that the method of the present invention can provide a laminate with good adhesion between the polymer coating and the substrate even when the thickness of the polymer coating is very thin.
  Below, the preferable aspect of this invention is shown.
[1] A method for preparing a laminate comprising a substrate having a thermoplastic polymer resin coating on its surface, and further comprising a peelable release layer in contact with a surface remote from the thermoplastic polymer resin substrate. The method comprises:
  Forming or providing a substrate layer;
  Providing a thermoplastic polymer resin coating and a peelable release layer on the surface, wherein the peelable release layer is at least 30% of the thickness of the thermoplastic polymer resin coating, and the thermoplastic polymer resin Is 10 to 10,000 sec according to ISO 11443 standard^-1The minimum viscosity is about 3000 Pa. Measured at a temperature just above the melting point of the thermoplastic polymer resin and the maximum is just above the processing temperature of the thermoplastic polymer resin. less than s.
[2] The method according to [1], wherein the thermoplastic polymer resin coating and the peelable release layer are coextruded on the substrate.
[3] 10 to 10,000 sec^-1At a temperature 20 to 40 ° C. higher than the melting point of the thermoplastic polymer resin, the viscosity of the thermoplastic polymer resin measured according to the ISO 11443 standard is about 3000 Pa.s. The method according to [2], wherein the method is less than s.
[4] The viscosity of the thermoplastic polymer resin measured according to the ISO 11443 standard is about 40 to about 1000 Pa.s. The method according to [1], wherein s.
[5] The method of [1], further comprising the step of removing the release layer and optionally recycling the peelable release layer.
[6] The method according to [1], wherein the thickness of the thermoplastic polymer resin coating is less than about 50 μm.
[7] The method according to [1], wherein a thickness of the peelable release layer is thinner than a thickness of the thermoplastic polymer resin coating.
[8] The method according to [1], wherein the peelable release layer contains polyethylene or polypropylene.
[9] The method according to [1], further comprising a step of co-extruding a linking layer together with the thermoplastic polymer resin.
[10] The method according to [9], wherein the thickness of the coupling layer is thinner than the thickness of the thermoplastic polymer resin layer.
[11] The method according to [1], wherein the substrate contains a polyolefin.
[12] The method according to [1], wherein the thermoplastic layer includes one or more copolyetherester elastomers.
[13] A method for preparing a laminate comprising a substrate having a thermoplastic polymer resin coating on its surface, and further comprising a peelable release layer in contact with a surface remote from the thermoplastic polymer resin substrate. The method comprises:
  Forming or providing a substrate layer;
  Providing a thermoplastic polymer resin coating and a peelable release layer on the surface, wherein the peelable release layer is at least 30% of the thickness of the thermoplastic polymer resin coating, and the thermoplastic polymer resin Is 10 to 10,000 sec according to ISO 11443 standard^-1The minimum viscosity is about 3000 Pa. Measured at a temperature just above the melting point of the thermoplastic polymer resin and the maximum is just above the processing temperature of the thermoplastic polymer resin. a method that is less than s,
  The thermoplastic polymer resin includes one or more copolyetherester elastomers, and the copolyetherester elastomer has a plurality of repeating long-chain ester units and short-chain ester units head-to-tail bonded with ester bonds, and the long The chain ester unit is represented by the formula:
[Chemical Formula 3]

The short chain ester unit is represented by the following formula:
[Formula 4]

Where
  G is a divalent group remaining after removal of the terminal hydroxyl group from the poly (alkylene oxide) glycol having an average molecular weight of about 400-3500, and is incorporated into the one or more copolyetheresters by poly (alkylene oxide) glycol The amount of ethylene oxide groups produced is from about 25 to about 68% by weight, based on the total weight of the copolyetherester,
  R is a divalent group remaining after removal of the carboxyl group from a dicarboxylic acid having a molecular weight of less than about 300;
  D is a divalent group remaining after removal of the hydroxyl group from a diol having a molecular weight of less than about 250;
  The process wherein the copolyetherester contains from about 25 to about 80 weight percent short chain ester units.
[14] The substrate comprises polyolefin, the tie layer comprises a copolymer of ethylene and vinyl acetate, and the thermoplastic polymer resin comprises one or more copolyetheresters [9] or [10 ] Method.
[15] MVTR_CASIs the water vapor transmission rate (MVTR) from the copolyetherester-containing layer and the linking layer toward the substrate, and MVTR_SACIs a MVTR from the substrate layer toward the linking layer and the copolyetherester-containing layer._CAS> MVTR_SAC[14] The method according to [14].
[16] MVTR ratio is MVTR_CAS/ MVTR_SACThe method according to [15], characterized in that the resulting laminate has an MVTR of at least about 1.5.
[17] The water vapor transmission rate (MVTR) of the tie layer according to ASTM E96-66 (BW method) is about 100 to about 2000 g / m with a 25 micron thick test piece.²/ The method according to [14], wherein the method is 24 hours.
[18] The water vapor transmission rate (MVTR) of the copolyetherester-containing layer according to ASTM E96-66 (BW method) in a 25 micron thick specimen is at least about 2500 g / m²/ The method according to [12] or 13, characterized in that it is 24 hours.
[19] The method according to [5] or [9], wherein the obtained laminate has an adhesive strength between the substrate layer and the thermoplastic polymer resin measured according to ISO 2411 of at least 1 N / m. .
[20] In the obtained laminate, the thermoplastic polymer resin coating has a thickness of less than about 35 μm, and the adhesive strength between the base layer and the polymer resin coating is at least 3 N / m. 14].
[21] Use of a laminate obtainable by the method according to [1] or [14] as a waterproof water vapor permeable membrane.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating a coextrusion method of the present invention for producing a three-layer laminate structure.
FIG. 2 is a cross-sectional view of a three-layer laminate structure obtained by the method of the present invention.

Claims (1)

A substrate having a thermoplastic polymer resin coating on its surface, and further including a release layer in contact with a surface remote from the thermoplastic polymer resin substrate, the release layer being peelable from the thermoplastic polymer resin A method of preparing a laminate, the method comprising:
Forming a substrate layer;
Coextruding a thermoplastic polymer resin coating and a release layer on the surface of the substrate;
The release layer has a thickness less than the thickness of the thermoplastic polymer resin coating;
When T _RL is the thickness of the release layer and T _CL is the thickness of the thermoplastic polymer resin coating, T _RL / T _CL is greater than 0.3;
The thermoplastic polymer resin has a viscosity of 3000 Pa. When measured according to the ISO 11443 standard in a temperature range of 200 to 250 ° C. have a viscosity of less than s,
The substrate comprises a polyolefin;
The release layer comprises polyethylene or polypropylene,
The thermoplastic polymer resin includes one or more copolyether ester elastomers, the copolyether ester elastomers having a plurality of repeating long chain ester units and short chain ester units bonded head-to-tail with ester bonds, The long chain ester unit is represented by the following formula:

The short chain ester unit is represented by the following formula:

Where
G is a divalent group remaining after removal of the terminal hydroxyl group from poly (alkylene oxide) glycol having an average molecular weight of 400 to 3500, and is incorporated into the one or more copolyetheresters by poly (alkylene oxide) glycol The amount of ethylene oxide groups is 25 to 68% by weight, based on the total weight of the copolyetherester,
R is a divalent group remaining after removing a carboxyl group from a dicarboxylic acid having a molecular weight of less than 300;
D is a divalent group remaining after removing a hydroxyl group from a diol having a molecular weight of less than 250;
The method wherein the copolyetherester contains 25 to 80 wt% of short chain ester units .

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